21100806100 has 72 divisors (see below), whose sum is σ = 49974176448. Its totient is φ = 7669516800.

The previous prime is 21100806091. The next prime is 21100806131. The reversal of 21100806100 is 160800112.

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, 4768489 + ... + 4772911.

It is an arithmetic number, because the mean of its divisors is an integer number (694085784).

Almost surely, 2^21100806100 is an apocalyptic number.

21100806100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21100806100 is an abundant number, since it is smaller than the sum of its proper divisors (28873370348).

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

21100806100 is a wasteful number, since it uses less digits than its factorization.

21100806100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8785 (or 8778 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 19.

The spelling of 21100806100 in words is "twenty-one billion, one hundred million, eight hundred six thousand, one hundred".