81863957775600 has 720 divisors, whose sum is σ = 381436445505024. Its totient is φ = 15702177024000.

The previous prime is 81863957775583. The next prime is 81863957775623. The reversal of 81863957775600 is 657775936818.

81863957775600 is a `hidden beast` number, since 8 + 1 + 8 + 6 + 3 + 9 + 5 + 7 + 7 + 7 + 5 + 600 = 666.

81863957775600 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (720).

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 7755036 + ... + 14962235.

Almost surely, 2^{81863957775600} is an apocalyptic number.

81863957775600 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81863957775600 is an abundant number, since it is smaller than the sum of its proper divisors (299572487729424).

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

81863957775600 is a wasteful number, since it uses less digits than its factorization.

81863957775600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22717326 (or 22717312 counting only the distinct ones).

The product of its (nonzero) digits is 533433600, while the sum is 72.

The spelling of 81863957775600 in words is "eighty-one trillion, eight hundred sixty-three billion, nine hundred fifty-seven million, seven hundred seventy-five thousand, six hundred".