81871939685376 has 132 divisors (see below), whose sum is σ = 239251685668632. Its totient is φ = 26961843339264.

The previous prime is 81871939685369. The next prime is 81871939685383. The reversal of 81871939685376 is 67358693917818.

81871939685376 is a `hidden beast` number, since 8 + 1 + 8 + 7 + 19 + 3 + 9 + 68 + 537 + 6 = 666.

It is an interprime number because it is at equal distance from previous prime (81871939685369) and next prime (81871939685383).

It is a super-2 number, since 2×81871939685376² (a number of 29 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81871939685295 and 81871939685304.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 52751181 + ... + 54281036.

Almost surely, 2^{81871939685376} is an apocalyptic number.

It is an amenable number.

81871939685376 is an abundant number, since it is smaller than the sum of its proper divisors (157379745983256).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81871939685376 is a wasteful number, since it uses less digits than its factorization.

81871939685376 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107032326 (or 107032305 counting only the distinct ones).

The product of its digits is 3292047360, while the sum is 81.

The spelling of 81871939685376 in words is "eighty-one trillion, eight hundred seventy-one billion, nine hundred thirty-nine million, six hundred eighty-five thousand, three hundred seventy-six".