72164421 has 24 divisors (see below), whose sum is σ = 119381184. Its totient is φ = 41149440.

The previous prime is 72164401. The next prime is 72164423. The reversal of 72164421 is 12446127.

72164421 is a `hidden beast` number, since 7 + 216 + 442 + 1 = 666.

It is not a de Polignac number, because 72164421 - 2¹⁸ = 71902277 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72164423) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 39490 + ... + 41276.

It is an arithmetic number, because the mean of its divisors is an integer number (4974216).

Almost surely, 2^72164421 is an apocalyptic number.

It is an amenable number.

72164421 is a deficient number, since it is larger than the sum of its proper divisors (47216763).

72164421 is a wasteful number, since it uses less digits than its factorization.

72164421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2441 (or 2438 counting only the distinct ones).

The product of its digits is 2688, while the sum is 27.

The square root of 72164421 is about 8494.9644496019. The cubic root of 72164421 is about 416.3331992878. Note that the first 3 decimals are identical.

The spelling of 72164421 in words is "seventy-two million, one hundred sixty-four thousand, four hundred twenty-one".