21331321100 has 18 divisors (see below), whose sum is σ = 46288967004. Its totient is φ = 8532528400.

The previous prime is 21331321097. The next prime is 21331321111. The reversal of 21331321100 is 112313312.

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, 106656506 + ... + 106656705.

It is an arithmetic number, because the mean of its divisors is an integer number (2571609278).

Almost surely, 2^21331321100 is an apocalyptic number.

21331321100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21331321100 is an abundant number, since it is smaller than the sum of its proper divisors (24957645904).

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

21331321100 is a wasteful number, since it uses less digits than its factorization.

21331321100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213313225 (or 213313218 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 17.

Adding to 21331321100 its reverse (112313312), we get a palindrome (21443634412).

The spelling of 21331321100 in words is "twenty-one billion, three hundred thirty-one million, three hundred twenty-one thousand, one hundred".