81612759915 has 12 divisors (see below), whose sum is σ = 141462117264. Its totient is φ = 43526805264.

The previous prime is 81612759857. The next prime is 81612759919. The reversal of 81612759915 is 51995721618.

It is a happy number.

81612759915 is a `hidden beast` number, since 8 + 1 + 612 + 7 + 5 + 9 + 9 + 15 = 666.

It is not a de Polignac number, because 81612759915 - 2⁸ = 81612759659 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81612759919) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 906808399 + ... + 906808488.

It is an arithmetic number, because the mean of its divisors is an integer number (11788509772).

Almost surely, 2^81612759915 is an apocalyptic number.

81612759915 is a deficient number, since it is larger than the sum of its proper divisors (59849357349).

81612759915 is a wasteful number, since it uses less digits than its factorization.

81612759915 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1813616898 (or 1813616895 counting only the distinct ones).

The product of its digits is 1360800, while the sum is 54.

The spelling of 81612759915 in words is "eighty-one billion, six hundred twelve million, seven hundred fifty-nine thousand, nine hundred fifteen".