72644731 has 4 divisors (see below), whose sum is σ = 72860632. Its totient is φ = 72428832.

The previous prime is 72644713. The next prime is 72644783. The reversal of 72644731 is 13744627.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13744627 = 13 ⋅1057279.

It is a cyclic number.

It is not a de Polignac number, because 72644731 - 2¹⁵ = 72611963 is a prime.

It is a super-2 number, since 2×72644731² = 10554513884124722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72644701) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 107445 + ... + 108118.

It is an arithmetic number, because the mean of its divisors is an integer number (18215158).

Almost surely, 2^72644731 is an apocalyptic number.

72644731 is a deficient number, since it is larger than the sum of its proper divisors (215901).

72644731 is a wasteful number, since it uses less digits than its factorization.

72644731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215900.

The product of its digits is 28224, while the sum is 34.

The square root of 72644731 is about 8523.1878425857. The cubic root of 72644731 is about 417.2548306586.

The spelling of 72644731 in words is "seventy-two million, six hundred forty-four thousand, seven hundred thirty-one".