72102731 has 2 divisors, whose sum is σ = 72102732. Its totient is φ = 72102730.

The previous prime is 72102707. The next prime is 72102761. The reversal of 72102731 is 13720127.

It is a weak prime.

It is an emirp because it is prime and its reverse (13720127) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 72102731 - 2²⁶ = 4993867 is a prime.

It is a super-2 number, since 2×72102731² = 10397607635316722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 72102697 and 72102706.

It is not a weakly prime, because it can be changed into another prime (72102761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36051365 + 36051366.

It is an arithmetic number, because the mean of its divisors is an integer number (36051366).

Almost surely, 2^72102731 is an apocalyptic number.

72102731 is a deficient number, since it is larger than the sum of its proper divisors (1).

72102731 is an equidigital number, since it uses as much as digits as its factorization.

72102731 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 588, while the sum is 23.

The square root of 72102731 is about 8491.3326986993. The cubic root of 72102731 is about 416.2145308509.

Adding to 72102731 its reverse (13720127), we get a palindrome (85822858).

The spelling of 72102731 in words is "seventy-two million, one hundred two thousand, seven hundred thirty-one".