21012122200 has 48 divisors (see below), whose sum is σ = 48865042080. Its totient is φ = 8402808960.

The previous prime is 21012122191. The next prime is 21012122227. The reversal of 21012122200 is 222121012.

It is a happy number.

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, 1023234 + ... + 1043566.

It is an arithmetic number, because the mean of its divisors is an integer number (1018021710).

Almost surely, 2^21012122200 is an apocalyptic number.

21012122200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21012122200 is an abundant number, since it is smaller than the sum of its proper divisors (27852919880).

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

21012122200 is a wasteful number, since it uses less digits than its factorization.

21012122200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25516 (or 25507 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21012122200 its reverse (222121012), we get a palindrome (21234243212).

The spelling of 21012122200 in words is "twenty-one billion, twelve million, one hundred twenty-two thousand, two hundred".