721621344 has 24 divisors (see below), whose sum is σ = 1894256280. Its totient is φ = 240540416.

The previous prime is 721621337. The next prime is 721621357. The reversal of 721621344 is 443126127.

It is a tau number, because it is divible by the number of its divisors (24).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3758349 + ... + 3758540.

It is an arithmetic number, because the mean of its divisors is an integer number (78927345).

Almost surely, 2^721621344 is an apocalyptic number.

It is an amenable number.

721621344 is an abundant number, since it is smaller than the sum of its proper divisors (1172634936).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

721621344 is a wasteful number, since it uses less digits than its factorization.

721621344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7516902 (or 7516894 counting only the distinct ones).

The product of its digits is 8064, while the sum is 30.

The square root of 721621344 is about 26863.0107024511. The cubic root of 721621344 is about 896.9532133453.

The spelling of 721621344 in words is "seven hundred twenty-one million, six hundred twenty-one thousand, three hundred forty-four".