21857478792 has 64 divisors (see below), whose sum is σ = 54997704000. Its totient is φ = 7238778624.

The previous prime is 21857478787. The next prime is 21857478829. The reversal of 21857478792 is 29787475812.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2442358 + ... + 2451290.

It is an arithmetic number, because the mean of its divisors is an integer number (859339125).

Almost surely, 2^21857478792 is an apocalyptic number.

It is an amenable number.

21857478792 is an abundant number, since it is smaller than the sum of its proper divisors (33140225208).

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

21857478792 is a wasteful number, since it uses less digits than its factorization.

21857478792 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9590 (or 9586 counting only the distinct ones).

The product of its digits is 15805440, while the sum is 60.

The spelling of 21857478792 in words is "twenty-one billion, eight hundred fifty-seven million, four hundred seventy-eight thousand, seven hundred ninety-two".