81574948972 has 36 divisors (see below), whose sum is σ = 156943555888. Its totient is φ = 37072490400.

The previous prime is 81574948969. The next prime is 81574948979. The reversal of 81574948972 is 27984947518.

It is not an unprimeable number, because it can be changed into a prime (81574948979) 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, 3211273 + ... + 3236575.

Almost surely, 2^81574948972 is an apocalyptic number.

It is an amenable number.

81574948972 is a deficient number, since it is larger than the sum of its proper divisors (75368606916).

81574948972 is a wasteful number, since it uses less digits than its factorization.

81574948972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31990 (or 31977 counting only the distinct ones).

The product of its digits is 40642560, while the sum is 64.

The spelling of 81574948972 in words is "eighty-one billion, five hundred seventy-four million, nine hundred forty-eight thousand, nine hundred seventy-two".