721635770052 has 18 divisors (see below), whose sum is σ = 1824134863278. Its totient is φ = 240545256672.

The previous prime is 721635770047. The next prime is 721635770203. The reversal of 721635770052 is 250077536127.

721635770052 is a `hidden beast` number, since 7 + 2 + 1 + 635 + 7 + 7 + 0 + 0 + 5 + 2 = 666.

721635770052 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 612375111936 + 109260658116 = 782544^2 + 330546^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-4 number, since 4×721635770052⁴ (a number of 49 digits) contains 4444 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 10022718993 + ... + 10022719064.

Almost surely, 2^721635770052 is an apocalyptic number.

It is an amenable number.

721635770052 is an abundant number, since it is smaller than the sum of its proper divisors (1102499093226).

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

721635770052 is a wasteful number, since it uses less digits than its factorization.

721635770052 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20045438067 (or 20045438062 counting only the distinct ones).

The product of its (nonzero) digits is 617400, while the sum is 45.

The spelling of 721635770052 in words is "seven hundred twenty-one billion, six hundred thirty-five million, seven hundred seventy thousand, fifty-two".