202121111122121 has 4 divisors (see below), whose sum is σ = 204122310242244. Its totient is φ = 200119912002000.

The previous prime is 202121111122067. The next prime is 202121111122157. The reversal of 202121111122121 is 121221111121202.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 174108025000000 + 28013086122121 = 13195000^2 + 5292739^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-202121111122121 is a prime.

It is a super-2 number, since 2×202121111122121² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 202121111122093 and 202121111122102.

It is not an unprimeable number, because it can be changed into a prime (202121111121121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1000599559910 + ... + 1000599560111.

It is an arithmetic number, because the mean of its divisors is an integer number (51030577560561).

Almost surely, 2^{202121111122121} is an apocalyptic number.

It is an amenable number.

202121111122121 is a deficient number, since it is larger than the sum of its proper divisors (2001199120123).

202121111122121 is a wasteful number, since it uses less digits than its factorization.

202121111122121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2001199120122.

The product of its (nonzero) digits is 64, while the sum is 20.

Adding to 202121111122121 its reverse (121221111121202), we get a palindrome (323342222243323).

The spelling of 202121111122121 in words is "two hundred two trillion, one hundred twenty-one billion, one hundred eleven million, one hundred twenty-two thousand, one hundred twenty-one".