72730640 has 20 divisors (see below), whose sum is σ = 169098924. Its totient is φ = 29092224.

The previous prime is 72730633. The next prime is 72730661. The reversal of 72730640 is 4603727.

It can be written as a sum of positive squares in 2 ways, for example, as 41011216 + 31719424 = 6404^2 + 5632^2 .

It is a tau number, because it is divible by the number of its divisors (20).

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, 454487 + ... + 454646.

Almost surely, 2^72730640 is an apocalyptic number.

It is an amenable number.

72730640 is an abundant number, since it is smaller than the sum of its proper divisors (96368284).

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

72730640 is a wasteful number, since it uses less digits than its factorization.

72730640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 909146 (or 909140 counting only the distinct ones).

The product of its (nonzero) digits is 7056, while the sum is 29.

The square root of 72730640 is about 8528.2260758026. The cubic root of 72730640 is about 417.4192464562.

The spelling of 72730640 in words is "seventy-two million, seven hundred thirty thousand, six hundred forty".