21221211121200 has 180 divisors, whose sum is σ = 74372642184048. Its totient is φ = 5602959936000.

The previous prime is 21221211121181. The next prime is 21221211121213. The reversal of 21221211121200 is 212111212212.

21221211121200 is a `hidden beast` number, since 21 + 221 + 211 + 1 + 212 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (180).

It is a super-2 number, since 2×21221211121200² (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 35 ways as a sum of consecutive naturals, for example, 28818484 + ... + 29545683.

Almost surely, 2^{21221211121200} is an apocalyptic number.

21221211121200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21221211121200 is an abundant number, since it is smaller than the sum of its proper divisors (53151431062848).

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

21221211121200 is a wasteful number, since it uses less digits than its factorization.

21221211121200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58364292 (or 58364278 counting only the distinct ones).

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

Adding to 21221211121200 its reverse (212111212212), we get a palindrome (21433322333412).

The spelling of 21221211121200 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred eleven million, one hundred twenty-one thousand, two hundred".