72730621 has 4 divisors (see below), whose sum is σ = 72837792. Its totient is φ = 72623452.

The previous prime is 72730601. The next prime is 72730631. The reversal of 72730621 is 12603727.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 72730621 - 2⁵ = 72730589 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 72730621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72730601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52561 + ... + 53926.

It is an arithmetic number, because the mean of its divisors is an integer number (18209448).

Almost surely, 2^72730621 is an apocalyptic number.

It is an amenable number.

72730621 is a deficient number, since it is larger than the sum of its proper divisors (107171).

72730621 is a wasteful number, since it uses less digits than its factorization.

72730621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107170.

The product of its (nonzero) digits is 3528, while the sum is 28.

The square root of 72730621 is about 8528.2249618546. The cubic root of 72730621 is about 417.4192101076.

The spelling of 72730621 in words is "seventy-two million, seven hundred thirty thousand, six hundred twenty-one".