81001555004160 has 432 divisors, whose sum is σ = 327742352281344. Its totient is φ = 18084067319808.

The previous prime is 81001555004113. The next prime is 81001555004207. The reversal of 81001555004160 is 6140055510018.

81001555004160 is a `hidden beast` number, since 8 + 1 + 0 + 0 + 1 + 5 + 550 + 0 + 41 + 60 = 666.

It is an interprime number because it is at equal distance from previous prime (81001555004113) and next prime (81001555004207).

It is a super-2 number, since 2×81001555004160² (a number of 29 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 8212522 + ... + 15147561.

Almost surely, 2^{81001555004160} is an apocalyptic number.

81001555004160 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81001555004160 is an abundant number, since it is smaller than the sum of its proper divisors (246740797277184).

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

81001555004160 is a wasteful number, since it uses less digits than its factorization.

81001555004160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23360160 (or 23360143 counting only the distinct ones).

The product of its (nonzero) digits is 24000, while the sum is 36.

The spelling of 81001555004160 in words is "eighty-one trillion, one billion, five hundred fifty-five million, four thousand, one hundred sixty".