21857216292 has 36 divisors (see below), whose sum is σ = 55295472960. Its totient is φ = 7279766832.

The previous prime is 21857216279. The next prime is 21857216299. The reversal of 21857216292 is 29261275812.

21857216292 is a `hidden beast` number, since 2 + 18 + 5 + 7 + 2 + 1 + 629 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is not an unprimeable number, because it can be changed into a prime (21857216299) 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, 204192 + ... + 292247.

It is an arithmetic number, because the mean of its divisors is an integer number (1535985360).

Almost surely, 2^21857216292 is an apocalyptic number.

It is an amenable number.

21857216292 is an abundant number, since it is smaller than the sum of its proper divisors (33438256668).

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

21857216292 is a wasteful number, since it uses less digits than its factorization.

21857216292 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 497672 (or 497667 counting only the distinct ones).

The product of its digits is 241920, while the sum is 45.

The spelling of 21857216292 in words is "twenty-one billion, eight hundred fifty-seven million, two hundred sixteen thousand, two hundred ninety-two".