72781904 has 20 divisors (see below), whose sum is σ = 151862676. Its totient is φ = 33591552.

The previous prime is 72781889. The next prime is 72781921. The reversal of 72781904 is 40918727.

It can be written as a sum of positive squares in 2 ways, for example, as 4752400 + 68029504 = 2180^2 + 8248^2 .

It is a congruent 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, 174749 + ... + 175164.

Almost surely, 2^72781904 is an apocalyptic number.

It is an amenable number.

72781904 is an abundant number, since it is smaller than the sum of its proper divisors (79080772).

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

72781904 is a wasteful number, since it uses less digits than its factorization.

72781904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 349934 (or 349928 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 38.

The square root of 72781904 is about 8531.2310952171. The cubic root of 72781904 is about 417.5172957086.

The spelling of 72781904 in words is "seventy-two million, seven hundred eighty-one thousand, nine hundred four".