21212220112200 has 144 divisors (see below), whose sum is σ = 76717529490420. Its totient is φ = 5221469560320.

The previous prime is 21212220112183. The next prime is 21212220112217. The reversal of 21212220112200 is 221102221212.

It is a happy number.

21212220112200 is a `hidden beast` number, since 2 + 1 + 212 + 220 + 11 + 220 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (21212220112183) and next prime (21212220112217).

It can be written as a sum of positive squares in 6 ways, for example, as 2080396600164 + 19131823512036 = 1442358^2 + 4373994^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 453229167 + ... + 453275966.

Almost surely, 2^{21212220112200} is an apocalyptic number.

21212220112200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21212220112200 is an abundant number, since it is smaller than the sum of its proper divisors (55505309378220).

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

21212220112200 is a wasteful number, since it uses less digits than its factorization.

21212220112200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 906505168 (or 906505156 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21212220112200 its reverse (221102221212), we get a palindrome (21433322333412).

The spelling of 21212220112200 in words is "twenty-one trillion, two hundred twelve billion, two hundred twenty million, one hundred twelve thousand, two hundred".