72165931 has 2 divisors, whose sum is σ = 72165932. Its totient is φ = 72165930.

The previous prime is 72165889. The next prime is 72165941. The reversal of 72165931 is 13956127.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 72165931 - 2⁹ = 72165419 is a prime.

It is a super-2 number, since 2×72165931² = 10415843194193522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (72165941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36082965 + 36082966.

It is an arithmetic number, because the mean of its divisors is an integer number (36082966).

Almost surely, 2^72165931 is an apocalyptic number.

72165931 is a deficient number, since it is larger than the sum of its proper divisors (1).

72165931 is an equidigital number, since it uses as much as digits as its factorization.

72165931 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11340, while the sum is 34.

The square root of 72165931 is about 8495.0533253182. The cubic root of 72165931 is about 416.3361031137.

The spelling of 72165931 in words is "seventy-two million, one hundred sixty-five thousand, nine hundred thirty-one".