81996964 has 12 divisors (see below), whose sum is σ = 163993984. Its totient is φ = 35141544.

The previous prime is 81996947. The next prime is 81996973. The reversal of 81996964 is 46969918.

81996964 is an admirable number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1464204 + ... + 1464259.

Almost surely, 2^81996964 is an apocalyptic number.

It is an amenable number.

81996964 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81996964 is a wasteful number, since it uses less digits than its factorization.

81996964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2928474 (or 2928472 counting only the distinct ones).

The product of its digits is 839808, while the sum is 52.

The square root of 81996964 is about 9055.2175015292. The cubic root of 81996964 is about 434.4427867848.

The spelling of 81996964 in words is "eighty-one million, nine hundred ninety-six thousand, nine hundred sixty-four".