72511213 has 2 divisors, whose sum is σ = 72511214. Its totient is φ = 72511212.

The previous prime is 72511193. The next prime is 72511253. The reversal of 72511213 is 31211527.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 62758084 + 9753129 = 7922^2 + 3123^2 .

It is a cyclic number.

It is not a de Polignac number, because 72511213 - 2²¹ = 70414061 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72511253) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36255606 + 36255607.

It is an arithmetic number, because the mean of its divisors is an integer number (36255607).

Almost surely, 2^72511213 is an apocalyptic number.

It is an amenable number.

72511213 is a deficient number, since it is larger than the sum of its proper divisors (1).

72511213 is an equidigital number, since it uses as much as digits as its factorization.

72511213 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 420, while the sum is 22.

The square root of 72511213 is about 8515.3516075380. The cubic root of 72511213 is about 416.9990415320. Note that the first 3 decimals are identical.

It can be divided in two parts, 7251 and 1213, that added together give a square (8464 = 92²).

The spelling of 72511213 in words is "seventy-two million, five hundred eleven thousand, two hundred thirteen".