81970984637568 has 256 divisors, whose sum is σ = 264426757257600. Its totient is φ = 24845395120128.

The previous prime is 81970984637557. The next prime is 81970984637579. The reversal of 81970984637568 is 86573648907918.

81970984637568 is a `hidden beast` number, since 8 + 1 + 9 + 7 + 0 + 9 + 8 + 46 + 3 + 7 + 568 = 666.

It is an interprime number because it is at equal distance from previous prime (81970984637557) and next prime (81970984637579).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10605471 + ... + 16625822.

Almost surely, 2^{81970984637568} is an apocalyptic number.

It is an amenable number.

81970984637568 is an abundant number, since it is smaller than the sum of its proper divisors (182455772620032).

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

81970984637568 is a wasteful number, since it uses less digits than its factorization.

81970984637568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27231396 (or 27231378 counting only the distinct ones).

The product of its (nonzero) digits is 4389396480, while the sum is 81.

The spelling of 81970984637568 in words is "eighty-one trillion, nine hundred seventy billion, nine hundred eighty-four million, six hundred thirty-seven thousand, five hundred sixty-eight".