72157013 has 2 divisors, whose sum is σ = 72157014. Its totient is φ = 72157012.

The previous prime is 72156991. The next prime is 72157031. The reversal of 72157013 is 31075127.

Together with next prime (72157031) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 50794129 + 21362884 = 7127^2 + 4622^2 .

It is a cyclic number.

It is not a de Polignac number, because 72157013 - 2⁶ = 72156949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72157073) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36078506 + 36078507.

It is an arithmetic number, because the mean of its divisors is an integer number (36078507).

Almost surely, 2^72157013 is an apocalyptic number.

It is an amenable number.

72157013 is a deficient number, since it is larger than the sum of its proper divisors (1).

72157013 is an equidigital number, since it uses as much as digits as its factorization.

72157013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1470, while the sum is 26.

The square root of 72157013 is about 8494.5284153978. The cubic root of 72157013 is about 416.3189526464.

The spelling of 72157013 in words is "seventy-two million, one hundred fifty-seven thousand, thirteen".