722721639 has 12 divisors (see below), whose sum is σ = 1017017016. Its totient is φ = 456455088.

The previous prime is 722721613. The next prime is 722721647. The reversal of 722721639 is 936127227.

It is not a de Polignac number, because 722721639 - 2⁵ = 722721607 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 722721597 and 722721606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (722721539) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 332584 + ... + 334749.

It is an arithmetic number, because the mean of its divisors is an integer number (84751418).

Almost surely, 2^722721639 is an apocalyptic number.

722721639 is a deficient number, since it is larger than the sum of its proper divisors (294295377).

722721639 is a wasteful number, since it uses less digits than its factorization.

722721639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 667374 (or 667355 counting only the distinct ones).

The product of its digits is 63504, while the sum is 39.

The square root of 722721639 is about 26883.4826426934. The cubic root of 722721639 is about 897.4088594948.

The spelling of 722721639 in words is "seven hundred twenty-two million, seven hundred twenty-one thousand, six hundred thirty-nine".