21508138200 has 96 divisors (see below), whose sum is σ = 70597334160. Its totient is φ = 5398118400.

The previous prime is 21508138193. The next prime is 21508138243. The reversal of 21508138200 is 283180512.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1044121 + ... + 1064520.

Almost surely, 2^21508138200 is an apocalyptic number.

21508138200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21508138200 is an abundant number, since it is smaller than the sum of its proper divisors (49089195960).

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

21508138200 is a wasteful number, since it uses less digits than its factorization.

21508138200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2108677 (or 2108668 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 30.

The spelling of 21508138200 in words is "twenty-one billion, five hundred eight million, one hundred thirty-eight thousand, two hundred".