72621391 has 2 divisors, whose sum is σ = 72621392. Its totient is φ = 72621390.

The previous prime is 72621379. The next prime is 72621397. The reversal of 72621391 is 19312627.

It is a strong prime.

It is an emirp because it is prime and its reverse (19312627) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 72621391 - 2²⁵ = 39066959 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72621397) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36310695 + 36310696.

It is an arithmetic number, because the mean of its divisors is an integer number (36310696).

Almost surely, 2^72621391 is an apocalyptic number.

72621391 is a deficient number, since it is larger than the sum of its proper divisors (1).

72621391 is an equidigital number, since it uses as much as digits as its factorization.

72621391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4536, while the sum is 31.

The square root of 72621391 is about 8521.8185265822. The cubic root of 72621391 is about 417.2101393195.

The spelling of 72621391 in words is "seventy-two million, six hundred twenty-one thousand, three hundred ninety-one".