81600791967 has 24 divisors (see below), whose sum is σ = 118830393344. Its totient is φ = 53956509264.

The previous prime is 81600791963. The next prime is 81600792001. The reversal of 81600791967 is 76919700618.

It is not a de Polignac number, because 81600791967 - 2² = 81600791963 is a prime.

It is a super-2 number, since 2×81600791967² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81600791963) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 4978728 + ... + 4995090.

Almost surely, 2^81600791967 is an apocalyptic number.

81600791967 is a deficient number, since it is larger than the sum of its proper divisors (37229601377).

81600791967 is a wasteful number, since it uses less digits than its factorization.

81600791967 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20859 (or 20856 counting only the distinct ones).

The product of its (nonzero) digits is 1143072, while the sum is 54.

The spelling of 81600791967 in words is "eighty-one billion, six hundred million, seven hundred ninety-one thousand, nine hundred sixty-seven".