72318013 has 2 divisors, whose sum is σ = 72318014. Its totient is φ = 72318012.

The previous prime is 72317989. The next prime is 72318019. The reversal of 72318013 is 31081327.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65901924 + 6416089 = 8118^2 + 2533^2 .

It is a cyclic number.

It is not a de Polignac number, because 72318013 - 2⁹ = 72317501 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72318019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36159006 + 36159007.

It is an arithmetic number, because the mean of its divisors is an integer number (36159007).

Almost surely, 2^72318013 is an apocalyptic number.

It is an amenable number.

72318013 is a deficient number, since it is larger than the sum of its proper divisors (1).

72318013 is an equidigital number, since it uses as much as digits as its factorization.

72318013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1008, while the sum is 25.

The square root of 72318013 is about 8503.9998236124. Note that the first 3 decimals coincide. The cubic root of 72318013 is about 416.6283592160.

The spelling of 72318013 in words is "seventy-two million, three hundred eighteen thousand, thirteen".