81260915157792 has 72 divisors (see below), whose sum is σ = 231086663920476. Its totient is φ = 27086861953536.

The previous prime is 81260915157727. The next prime is 81260915157803. The reversal of 81260915157792 is 29775151906218.

81260915157792 is a `hidden beast` number, since 8 + 1 + 2 + 6 + 0 + 9 + 1 + 51 + 577 + 9 + 2 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 62410695201936 + 18850219955856 = 7900044^2 + 4341684^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 103379758 + ... + 104162834.

Almost surely, 2^{81260915157792} is an apocalyptic number.

It is an amenable number.

81260915157792 is an abundant number, since it is smaller than the sum of its proper divisors (149825748762684).

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

81260915157792 is a wasteful number, since it uses less digits than its factorization.

81260915157792 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1143410 (or 1143399 counting only the distinct ones).

The product of its (nonzero) digits is 19051200, while the sum is 63.

The spelling of 81260915157792 in words is "eighty-one trillion, two hundred sixty billion, nine hundred fifteen million, one hundred fifty-seven thousand, seven hundred ninety-two".