72644257 has 16 divisors (see below), whose sum is σ = 84188160. Its totient is φ = 61399872.

The previous prime is 72644233. The next prime is 72644269. The reversal of 72644257 is 75244627.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72644257 is a prime.

Its product of digits (94080) is a multiple of the sum of its prime divisors (672).

It is not an unprimeable number, because it can be changed into a prime (72644207) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 269919 + ... + 270187.

It is an arithmetic number, because the mean of its divisors is an integer number (5261760).

Almost surely, 2^72644257 is an apocalyptic number.

It is an amenable number.

72644257 is a deficient number, since it is larger than the sum of its proper divisors (11543903).

72644257 is a wasteful number, since it uses less digits than its factorization.

72644257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 672.

The product of its digits is 94080, while the sum is 37.

The square root of 72644257 is about 8523.1600360430. The cubic root of 72644257 is about 417.2539231405.

The spelling of 72644257 in words is "seventy-two million, six hundred forty-four thousand, two hundred fifty-seven".