72312640 has 28 divisors (see below), whose sum is σ = 172195236. Its totient is φ = 28924928.

The previous prime is 72312629. The next prime is 72312673. The reversal of 72312640 is 4621327.

72312640 = T₁₁₈ + T₁₁₉ + ... + T₇₅₇.

It can be written as a sum of positive squares in 2 ways, for example, as 41576704 + 30735936 = 6448^2 + 5544^2 .

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, 112669 + ... + 113308.

Almost surely, 2^72312640 is an apocalyptic number.

It is an amenable number.

72312640 is an abundant number, since it is smaller than the sum of its proper divisors (99882596).

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

72312640 is a wasteful number, since it uses less digits than its factorization.

72312640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225994 (or 225984 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 25.

The square root of 72312640 is about 8503.6839075779. The cubic root of 72312640 is about 416.6180409033.

Adding to 72312640 its reverse (4621327), we get a palindrome (76933967).

The spelling of 72312640 in words is "seventy-two million, three hundred twelve thousand, six hundred forty".