21557633304 has 16 divisors (see below), whose sum is σ = 53894083320. Its totient is φ = 7185877760.

The previous prime is 21557633299. The next prime is 21557633323. The reversal of 21557633304 is 40333675512.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 449117337 + ... + 449117384.

Almost surely, 2^21557633304 is an apocalyptic number.

21557633304 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21557633304 is an abundant number, since it is smaller than the sum of its proper divisors (32336450016).

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

21557633304 is a wasteful number, since it uses less digits than its factorization.

21557633304 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 898234730 (or 898234726 counting only the distinct ones).

The product of its (nonzero) digits is 226800, while the sum is 39.

The spelling of 21557633304 in words is "twenty-one billion, five hundred fifty-seven million, six hundred thirty-three thousand, three hundred four".