21221111212200 has 72 divisors (see below), whose sum is σ = 71267565160350. Its totient is φ = 5658962989440.

The previous prime is 21221111212193. The next prime is 21221111212229. The reversal of 21221111212200 is 221211112212.

21221111212200 is a `hidden beast` number, since 21 + 221 + 1 + 11 + 212 + 200 = 666.

21221111212200 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 20465870262084 + 755240950116 = 4523922^2 + 869046^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a super-2 number, since 2×21221111212200² (a number of 27 digits) contains 22 as substring.

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 17 ways as a sum of consecutive naturals, for example, 5894751315 + ... + 5894754914.

Almost surely, 2^{21221111212200} is an apocalyptic number.

21221111212200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21221111212200 is an abundant number, since it is smaller than the sum of its proper divisors (50046453948150).

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

21221111212200 is a wasteful number, since it uses less digits than its factorization.

21221111212200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11789506251 (or 11789506239 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21221111212200 its reverse (221211112212), we get a palindrome (21442322324412).

The spelling of 21221111212200 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred eleven million, two hundred twelve thousand, two hundred".