72631621 has 2 divisors, whose sum is σ = 72631622. Its totient is φ = 72631620.

The previous prime is 72631613. The next prime is 72631639. The reversal of 72631621 is 12613627.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50211396 + 22420225 = 7086^2 + 4735^2 .

It is a cyclic number.

It is not a de Polignac number, because 72631621 - 2³ = 72631613 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 72631621.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72631421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36315810 + 36315811.

It is an arithmetic number, because the mean of its divisors is an integer number (36315811).

Almost surely, 2^72631621 is an apocalyptic number.

It is an amenable number.

72631621 is a deficient number, since it is larger than the sum of its proper divisors (1).

72631621 is an equidigital number, since it uses as much as digits as its factorization.

72631621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3024, while the sum is 28.

The square root of 72631621 is about 8522.4187294453. The cubic root of 72631621 is about 417.2297288613.

The spelling of 72631621 in words is "seventy-two million, six hundred thirty-one thousand, six hundred twenty-one".