72645720 has 128 divisors (see below), whose sum is σ = 250905600. Its totient is φ = 16482816.

The previous prime is 72645719. The next prime is 72645733. The reversal of 72645720 is 2754627.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 165261 + ... + 165699.

It is an arithmetic number, because the mean of its divisors is an integer number (1960200).

Almost surely, 2^72645720 is an apocalyptic number.

72645720 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 72645720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (125452800).

72645720 is an abundant number, since it is smaller than the sum of its proper divisors (178259880).

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

72645720 is a wasteful number, since it uses less digits than its factorization.

72645720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 657 (or 653 counting only the distinct ones).

The product of its (nonzero) digits is 23520, while the sum is 33.

The square root of 72645720 is about 8523.2458605862. The cubic root of 72645720 is about 417.2567241804.

The spelling of 72645720 in words is "seventy-two million, six hundred forty-five thousand, seven hundred twenty".