Numbers have thin skins. And they’re easily replaced. Take 71624133. Here it is permuting its pellicles:

71624133 in base 10 = 100010001001110010111000101 in base 2 = 11222202212211200 in b3 = 10101032113011 in b4 = 121313433013 in b5 = 11035053113 in b6 = 1526536500 in b7 = 421162705 in b8 = 158685750 in b9 = 374802A9 in b11 = 1BBA1199 in b12 = 11AB9B59 in b13 = 9726137 in b14 = 644BE73 in b15 = F3855B7 in b16

But if digits are the skin of 71624133, what are its bones? Well, you could say the skeleton of a number, something that doesn’t change from base to base, is its prime factorization:

71624133 = 3² × 7² × 162413

But the primes themselves are numbers, so they’re wearing pellicles too. And it turns out that, in base 10, the pellicles of the prime factors of 71624133 match the pellicle of 71624133 itself:

71624133 = 3².7².162413

Here’s a list of primal pellicles in base 10:

735 = 3.5.7²
3792 = 2⁴.3.79
1341275 = 5².13.4127
13115375 = 5³.7.13.1153
22940075 = 5².229.4007
29373375 = 3.5³.29.37.73
71624133 = 3².7².162413
311997175 = 5².7.17².31.199
319953792 = 2⁷.3.53.79.199
1019127375 = 3².5³.7.127.1019
1147983375 = 3.5³.7.11.83.479
1734009275 = 5².173.400927
5581625072 = 2⁴.5581.62507
7350032375 = 5³.7.23.73.5003
17370159615 = 3⁴.5.17.59.61.701
33061224492 = 2².3³.306122449
103375535837 = 7².37.103.553583
171167303912 = 2³.11.17².6730391
319383665913 = 3.13³.19.383.6659
533671737975 = 3⁴.5².17.53.367.797
2118067737975 = 3².5².7.79.211.80677
3111368374257 = 3.11².13².683.74257
3216177757191 = 3.7³.191.757.21617
3740437158475 = 5².37.4043715847
3977292332775 = 3.5².29².233.277.977
4417149692375 = 5³.7.23.4969.44171
7459655393232 = 2⁴.3².7².23.45965539
7699132721175 = 3.5².7².27211.76991
7973529228735 = 3.5.7.97².2287.3529
10771673522535 = 3⁴.5.67.71.107.52253

You can find them at the Online Encyclopedia of Integer Sequences under A121342, “Composite numbers that are a concatenation of their distinct prime divisors in some order.” But what about pairs of primal pellicles, that is, pairs of numbers where the prime factors of each form the pellicle of the other?

35 = 5.7 ↔ 75 = 3.5²
1275 = 3.5².17 ↔ 3175 = 5².127
131715 = 3².5.2927 ↔ 329275 = 5².13171
3199767 = 3.359.2971 ↔ 35932971 = 3.19.67.97²
14931092 = 2².11.61.5563 ↔ 116155632 = 2⁴.3.109.149²

And here are a few primal pellicles I’ve found in other bases:

Primal Pellicles in Base 2

1111011011110 = 10.11¹⁰.110110111 in b2 = 7902 = 2.3².439 in b10
1110001100110111 = 11¹⁰.10111.100011001 in b2 = 58167 = 3².23.281 in b10
1111011011011110 = 10.11¹⁰.110110110111 in b2 = 63198 = 2.3².3511 in b10
11101001100001101 = 11¹⁰.101.101001100001 in b2 = 119565 = 3².5.2657 in b10
1111011011011011110 = 10.11¹⁰.110110110110111 in b2 = 505566 = 2.3².28087 in b10
1111011111101111011 = 11¹⁰.1011.10111.11011111 in b2 = 507771 = 3².11.23.223 in b10

Primal Pellicles in Base 3

121022 = 2¹⁰.12.102 in b3 = 440 = 2³.5.11 in b10
212212 = 2².21.212 in b3 = 644 = 2².7.23 in b10
20110112 = 2¹⁰.201.1011 in b3 = 4712 = 2³.19.31 in b10
21110110 = 10.21².1101 in b3 = 5439 = 3.7².37 in b10
121111101 = 12².111.1101 in b3 = 12025 = 5².13.37 in b10
222112121 = 2².21.221121 in b3 = 19348 = 2².7.691 in b10
2202122021 = 2².2021.22021 in b3 = 54412 = 2².61.223 in b10
120212201221 = 2.12².21.201.1202 in b3 = 312550 = 2.5².7.19.47 in b10

Primal Pellicles in Base 7

2525 = 2.5².25 in b7 = 950 = 2.5².19 in b10
3210 = 2.3⁴.10 in b7 = 1134 = 2.3⁴.7 in b10
5252 = 2.5².52 in b7 = 1850 = 2.5².37 in b10
332616 = 3³.16.326 in b7 = 58617 = 3³.13.167 in b10
336045 = 3².5.3604 in b7 = 59715 = 3².5.1327 in b10
2251635 = 2².3.5.16.25² in b7 = 281580 = 2².3.5.13.19² in b10

Primal Pellicles in Base 11

253 = 2².3.5² in b11 = 300 = 2².3.5² in b10
732 = 2.3².7² in b11 = 882 = 2.3².7² in b10
2123 = 2³.3³.12 in b11 = 2808 = 2³.3³.13 in b10
3432 = 2⁵.3.43 in b11 = 4512 = 2⁵.3.47 in b10
3710 = 3².7².10 in b11 = 4851 = 3².7².11 in b10
72252 = 2³.7².225 in b11 = 105448 = 2³.7².269 in b10

Primal Pellicles in Base 15

275 = 2⁴.5.7 in b15 = 560 = 2⁴.5.7 in b10
2D5 = 2.5².D in b15 = 650 = 2.5².13 in b10
2CD5 = 2.5².CD in b15 = 9650 = 2.5².193 in b10
7BE3 = 3.7².BE in b15 = 26313 = 3.7².179 in b10
21285 = 2⁴.5².128 in b15 = 105200 = 2⁴.5².263 in b10