21221201212200 has 216 divisors, whose sum is σ = 78335755884750. Its totient is φ = 5144533574400.

The previous prime is 21221201212171. The next prime is 21221201212231. The reversal of 21221201212200 is 221210212212.

It is a happy number.

21221201212200 is a `hidden beast` number, since 2 + 1 + 221 + 201 + 21 + 220 + 0 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 13806679158756 + 7414522053444 = 3715734^2 + 2722962^2 .

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 53 ways as a sum of consecutive naturals, for example, 48499375 + ... + 48934974.

Almost surely, 2^{21221201212200} is an apocalyptic number.

21221201212200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21221201212200 is an abundant number, since it is smaller than the sum of its proper divisors (57114554672550).

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

21221201212200 is a wasteful number, since it uses less digits than its factorization.

21221201212200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97434393 (or 97434370 counting only the distinct ones).

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

Adding to 21221201212200 its reverse (221210212212), we get a palindrome (21442411424412).

The spelling of 21221201212200 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred one million, two hundred twelve thousand, two hundred".