81599601995 has 16 divisors (see below), whose sum is σ = 100339458912. Its totient is φ = 63667395840.

The previous prime is 81599601961. The next prime is 81599602001. The reversal of 81599601995 is 59910699518.

It is not a de Polignac number, because 81599601995 - 2²⁴ = 81582824779 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 605684 + ... + 728046.

It is an arithmetic number, because the mean of its divisors is an integer number (6271216182).

Almost surely, 2^81599601995 is an apocalyptic number.

81599601995 is a deficient number, since it is larger than the sum of its proper divisors (18739856917).

81599601995 is a wasteful number, since it uses less digits than its factorization.

81599601995 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125662.

The product of its (nonzero) digits is 7873200, while the sum is 62.

The spelling of 81599601995 in words is "eighty-one billion, five hundred ninety-nine million, six hundred one thousand, nine hundred ninety-five".