81792904 has 16 divisors (see below), whose sum is σ = 153507420. Its totient is φ = 40857600.

The previous prime is 81792901. The next prime is 81792913. The reversal of 81792904 is 40929718.

It can be written as a sum of positive squares in 2 ways, for example, as 81540900 + 252004 = 9030^2 + 502^2 .

It is not an unprimeable number, because it can be changed into a prime (81792901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5352 + ... + 13864.

Almost surely, 2^81792904 is an apocalyptic number.

It is an amenable number.

81792904 is a deficient number, since it is larger than the sum of its proper divisors (71714516).

81792904 is a wasteful number, since it uses less digits than its factorization.

81792904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9720 (or 9716 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 40.

The square root of 81792904 is about 9043.9429454193. The cubic root of 81792904 is about 434.0820984798.

The spelling of 81792904 in words is "eighty-one million, seven hundred ninety-two thousand, nine hundred four".