72865631 has 2 divisors, whose sum is σ = 72865632. Its totient is φ = 72865630.

The previous prime is 72865613. The next prime is 72865643. The reversal of 72865631 is 13656827.

Together with previous prime (72865613) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is an emirp because it is prime and its reverse (13656827) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 72865631 - 2¹⁰ = 72864607 is a prime.

It is a super-2 number, since 2×72865631² = 10618800362056322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72865601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36432815 + 36432816.

It is an arithmetic number, because the mean of its divisors is an integer number (36432816).

Almost surely, 2^72865631 is an apocalyptic number.

72865631 is a deficient number, since it is larger than the sum of its proper divisors (1).

72865631 is an equidigital number, since it uses as much as digits as its factorization.

72865631 is an evil number, because the sum of its binary digits is even.

The product of its digits is 60480, while the sum is 38.

The square root of 72865631 is about 8536.1367725687. The cubic root of 72865631 is about 417.6773358305.

The spelling of 72865631 in words is "seventy-two million, eight hundred sixty-five thousand, six hundred thirty-one".