72164431 has 4 divisors (see below), whose sum is σ = 72826600. Its totient is φ = 71502264.

The previous prime is 72164423. The next prime is 72164459. The reversal of 72164431 is 13446127.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13446127 = 1279 ⋅10513.

It is a cyclic number.

It is not a de Polignac number, because 72164431 - 2³ = 72164423 is a prime.

It is a super-2 number, since 2×72164431² = 10415410203107522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 72164431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72164401) 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, 330921 + ... + 331138.

It is an arithmetic number, because the mean of its divisors is an integer number (18206650).

Almost surely, 2^72164431 is an apocalyptic number.

72164431 is a deficient number, since it is larger than the sum of its proper divisors (662169).

72164431 is a wasteful number, since it uses less digits than its factorization.

72164431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 662168.

The product of its digits is 4032, while the sum is 28.

The square root of 72164431 is about 8494.9650381859. The cubic root of 72164431 is about 416.3332185186. Note that the first 3 decimals are identical.

The spelling of 72164431 in words is "seventy-two million, one hundred sixty-four thousand, four hundred thirty-one".