721334644 has 12 divisors (see below), whose sum is σ = 1266396768. Its totient is φ = 359507000.

The previous prime is 721334597. The next prime is 721334651. The reversal of 721334644 is 446433127.

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, 288682 + ... + 291169.

It is an arithmetic number, because the mean of its divisors is an integer number (105533064).

Almost surely, 2^721334644 is an apocalyptic number.

It is an amenable number.

721334644 is a deficient number, since it is larger than the sum of its proper divisors (545062124).

721334644 is a wasteful number, since it uses less digits than its factorization.

721334644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 580166 (or 580164 counting only the distinct ones).

The product of its digits is 48384, while the sum is 34.

The square root of 721334644 is about 26857.6738382161. The cubic root of 721334644 is about 896.8344111729.

The spelling of 721334644 in words is "seven hundred twenty-one million, three hundred thirty-four thousand, six hundred forty-four".