21730762856 has 32 divisors (see below), whose sum is σ = 47063954880. Its totient is φ = 9296582400.

The previous prime is 21730762853. The next prime is 21730762861. The reversal of 21730762856 is 65826703712.

It is a self number, because there is not a number n which added to its sum of digits gives 21730762856.

It is not an unprimeable number, because it can be changed into a prime (21730762853) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7261460 + ... + 7264451.

It is an arithmetic number, because the mean of its divisors is an integer number (1470748590).

Almost surely, 2^21730762856 is an apocalyptic number.

It is an amenable number.

21730762856 is an abundant number, since it is smaller than the sum of its proper divisors (25333192024).

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

21730762856 is a wasteful number, since it uses less digits than its factorization.

21730762856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14525945 (or 14525941 counting only the distinct ones).

The product of its (nonzero) digits is 846720, while the sum is 47.

The spelling of 21730762856 in words is "twenty-one billion, seven hundred thirty million, seven hundred sixty-two thousand, eight hundred fifty-six".