21100212200 has 24 divisors (see below), whose sum is σ = 49057993830. Its totient is φ = 8440084800.

The previous prime is 21100212197. The next prime is 21100212223. The reversal of 21100212200 is 221200112.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 16305757636 + 4794454564 = 127694^2 + 69242^2 .

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, 52750331 + ... + 52750730.

Almost surely, 2^21100212200 is an apocalyptic number.

21100212200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21100212200 is an abundant number, since it is smaller than the sum of its proper divisors (27957781630).

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

21100212200 is a wasteful number, since it uses less digits than its factorization.

21100212200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105501077 (or 105501068 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21100212200 its reverse (221200112), we get a palindrome (21321412312).

The spelling of 21100212200 in words is "twenty-one billion, one hundred million, two hundred twelve thousand, two hundred".