72644631 has 4 divisors (see below), whose sum is σ = 96859512. Its totient is φ = 48429752.

The previous prime is 72644599. The next prime is 72644633. The reversal of 72644631 is 13644627.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13644627 = 3 ⋅4548209.

It is a cyclic number.

It is not a de Polignac number, because 72644631 - 2⁵ = 72644599 is a prime.

It is a super-2 number, since 2×72644631² = 10554484826252322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 72644592 and 72644601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72644633) 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, 12107436 + ... + 12107441.

It is an arithmetic number, because the mean of its divisors is an integer number (24214878).

Almost surely, 2^72644631 is an apocalyptic number.

72644631 is a deficient number, since it is larger than the sum of its proper divisors (24214881).

72644631 is a wasteful number, since it uses less digits than its factorization.

72644631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24214880.

The product of its digits is 24192, while the sum is 33.

The square root of 72644631 is about 8523.1819762340. The cubic root of 72644631 is about 417.2546391994.

The spelling of 72644631 in words is "seventy-two million, six hundred forty-four thousand, six hundred thirty-one".