2021200121 has 4 divisors (see below), whose sum is σ = 2021371044. Its totient is φ = 2021029200.

The previous prime is 2021200099. The next prime is 2021200157. The reversal of 2021200121 is 1210021202.

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 1736805625 + 284394496 = 41675^2 + 16864^2 .

It is a cyclic number.

It is not a de Polignac number, because 2021200121 - 2¹⁰ = 2021199097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2021200021) 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, 66290 + ... + 91851.

It is an arithmetic number, because the mean of its divisors is an integer number (505342761).

Almost surely, 2^2021200121 is an apocalyptic number.

It is an amenable number.

2021200121 is a deficient number, since it is larger than the sum of its proper divisors (170923).

2021200121 is a wasteful number, since it uses less digits than its factorization.

2021200121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170922.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 2021200121 is about 44957.7592969223. The cubic root of 2021200121 is about 1264.3571587332.

Adding to 2021200121 its reverse (1210021202), we get a palindrome (3231221323).

The spelling of 2021200121 in words is "two billion, twenty-one million, two hundred thousand, one hundred twenty-one".