21255853284 has 18 divisors (see below), whose sum is σ = 53730073670. Its totient is φ = 7085284416.

The previous prime is 21255853279. The next prime is 21255853303. The reversal of 21255853284 is 48235855212.

21255853284 is a `hidden beast` number, since 2 + 12 + 558 + 5 + 3 + 2 + 84 = 666.

It can be written as a sum of positive squares in only one way, i.e., 19564176384 + 1691676900 = 139872^2 + 41130^2 .

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

It is a super-2 number, since 2×21255853284² (a number of 21 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

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, 295220149 + ... + 295220220.

Almost surely, 2^21255853284 is an apocalyptic number.

It is an amenable number.

21255853284 is an abundant number, since it is smaller than the sum of its proper divisors (32474220386).

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

21255853284 is a wasteful number, since it uses less digits than its factorization.

21255853284 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 590440379 (or 590440374 counting only the distinct ones).

The product of its digits is 768000, while the sum is 45.

The spelling of 21255853284 in words is "twenty-one billion, two hundred fifty-five million, eight hundred fifty-three thousand, two hundred eighty-four".