72656257 has 2 divisors, whose sum is σ = 72656258. Its totient is φ = 72656256.

The previous prime is 72656251. The next prime is 72656261. The reversal of 72656257 is 75265627.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 67634176 + 5022081 = 8224^2 + 2241^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72656257 is a prime.

It is not a weakly prime, because it can be changed into another prime (72656251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36328128 + 36328129.

It is an arithmetic number, because the mean of its divisors is an integer number (36328129).

Almost surely, 2^72656257 is an apocalyptic number.

It is an amenable number.

72656257 is a deficient number, since it is larger than the sum of its proper divisors (1).

72656257 is an equidigital number, since it uses as much as digits as its factorization.

72656257 is an evil number, because the sum of its binary digits is even.

The product of its digits is 176400, while the sum is 40.

The square root of 72656257 is about 8523.8639712281. The cubic root of 72656257 is about 417.2768970667.

The spelling of 72656257 in words is "seventy-two million, six hundred fifty-six thousand, two hundred fifty-seven".