21221220012200 has 96 divisors (see below), whose sum is σ = 53141487399000. Its totient is φ = 7834522076160.

The previous prime is 21221220012133. The next prime is 21221220012233. The reversal of 21221220012200 is 221002212212.

It is a happy number.

It can be written as a sum of positive squares in 12 ways, for example, as 114123703684 + 21107096308516 = 337822^2 + 4594246^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19898126 + ... + 20937474.

Almost surely, 2^{21221220012200} is an apocalyptic number.

21221220012200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21221220012200 is an abundant number, since it is smaller than the sum of its proper divisors (31920267386800).

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

21221220012200 is a wasteful number, since it uses less digits than its factorization.

21221220012200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1047231 (or 1047222 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21221220012200 its reverse (221002212212), we get a palindrome (21442222224412).

The spelling of 21221220012200 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred twenty million, twelve thousand, two hundred".