202100000000121 has 12 divisors (see below), whose sum is σ = 291925862784660. Its totient is φ = 134731653073920.

The previous prime is 202100000000081. The next prime is 202100000000147. The reversal of 202100000000121 is 121000000001202.

It can be written as a sum of positive squares in 2 ways, for example, as 36346863514896 + 165753136485225 = 6028836^2 + 12874515^2 .

It is not a de Polignac number, because 202100000000121 - 2³¹ = 202097852516473 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (202100000000021) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 139259640 + ... + 140703401.

It is an arithmetic number, because the mean of its divisors is an integer number (24327155232055).

Almost surely, 2^{202100000000121} is an apocalyptic number.

It is an amenable number.

202100000000121 is a deficient number, since it is larger than the sum of its proper divisors (89825862784539).

202100000000121 is a wasteful number, since it uses less digits than its factorization.

202100000000121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280043256 (or 280043253 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 202100000000121 its reverse (121000000001202), we get a palindrome (323100000001323).

The spelling of 202100000000121 in words is "two hundred two trillion, one hundred billion, one hundred twenty-one", and thus it is an aban number.