202201212120021 has 80 divisors (see below), whose sum is σ = 304206941530800. Its totient is φ = 133842815188992.

The previous prime is 202201212120013. The next prime is 202201212120049. The reversal of 202201212120021 is 120021212102202.

It is a happy number.

202201212120021 is a `hidden beast` number, since 202 + 201 + 21 + 21 + 200 + 21 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 537639431121 + 201663572688900 = 733239^2 + 14200830^2 .

It is not a de Polignac number, because 202201212120021 - 2³ = 202201212120013 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 202201212119976 and 202201212120003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (202201212121021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 18881422615 + ... + 18881433323.

It is an arithmetic number, because the mean of its divisors is an integer number (3802586769135).

Almost surely, 2^{202201212120021} is an apocalyptic number.

It is an amenable number.

202201212120021 is a deficient number, since it is larger than the sum of its proper divisors (102005729410779).

202201212120021 is a wasteful number, since it uses less digits than its factorization.

202201212120021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13140 (or 13131 counting only the distinct ones).

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

Adding to 202201212120021 its reverse (120021212102202), we get a palindrome (322222424222223).

The spelling of 202201212120021 in words is "two hundred two trillion, two hundred one billion, two hundred twelve million, one hundred twenty thousand, twenty-one".