202102122100021 has 96 divisors (see below), whose sum is σ = 243514981100160. Its totient is φ = 166595013826560.

The previous prime is 202102122100007. The next prime is 202102122100051. The reversal of 202102122100021 is 120001221201202.

It is a happy number.

It is not a de Polignac number, because 202102122100021 - 2⁵ = 202102122099989 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 202102122099968 and 202102122100004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (202102122100051) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 9196063185 + ... + 9196085161.

It is an arithmetic number, because the mean of its divisors is an integer number (2536614386460).

Almost surely, 2^{202102122100021} is an apocalyptic number.

It is an amenable number.

202102122100021 is a deficient number, since it is larger than the sum of its proper divisors (41412859000139).

202102122100021 is a wasteful number, since it uses less digits than its factorization.

202102122100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22595 (or 22584 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 202102122100021 its reverse (120001221201202), we get a palindrome (322103343301223).

The spelling of 202102122100021 in words is "two hundred two trillion, one hundred two billion, one hundred twenty-two million, one hundred thousand, twenty-one".