21612459800 has 48 divisors (see below), whose sum is σ = 50372017800. Its totient is φ = 8623814400.

The previous prime is 21612459793. The next prime is 21612459811. The reversal of 21612459800 is 895421612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 50306 + ... + 213905.

Almost surely, 2^21612459800 is an apocalyptic number.

21612459800 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21612459800 is an abundant number, since it is smaller than the sum of its proper divisors (28759558000).

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

21612459800 is a wasteful number, since it uses less digits than its factorization.

21612459800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 264636 (or 264627 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 38.

The spelling of 21612459800 in words is "twenty-one billion, six hundred twelve million, four hundred fifty-nine thousand, eight hundred".