81315295792 has 80 divisors (see below), whose sum is σ = 163184868000. Its totient is φ = 39234004992.

The previous prime is 81315295759. The next prime is 81315295799. The reversal of 81315295792 is 29759251318.

It is a super-2 number, since 2×81315295792² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81315295799) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12844884 + ... + 12851212.

It is an arithmetic number, because the mean of its divisors is an integer number (2039810850).

Almost surely, 2^81315295792 is an apocalyptic number.

It is an amenable number.

81315295792 is an abundant number, since it is smaller than the sum of its proper divisors (81869572208).

81315295792 is a wasteful number, since it uses less digits than its factorization.

81315295792 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6638 (or 6632 counting only the distinct ones).

The product of its digits is 1360800, while the sum is 52.

The spelling of 81315295792 in words is "eighty-one billion, three hundred fifteen million, two hundred ninety-five thousand, seven hundred ninety-two".