2021202012121 has 4 divisors (see below), whose sum is σ = 2021332756644. Its totient is φ = 2021071267600.

The previous prime is 2021202012107. The next prime is 2021202012227. The reversal of 2021202012121 is 1212102021202.

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 911948601600 + 1109253410521 = 954960^2 + 1053211^2 .

It is a cyclic number.

It is not a de Polignac number, because 2021202012121 - 2²¹ = 2021199914969 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2021202012095 and 2021202012104.

It is not an unprimeable number, because it can be changed into a prime (2021202072121) 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, 65349070 + ... + 65379991.

It is an arithmetic number, because the mean of its divisors is an integer number (505333189161).

Almost surely, 2^{2021202012121} is an apocalyptic number.

It is an amenable number.

2021202012121 is a deficient number, since it is larger than the sum of its proper divisors (130744523).

2021202012121 is a wasteful number, since it uses less digits than its factorization.

2021202012121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130744522.

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

Adding to 2021202012121 its reverse (1212102021202), we get a palindrome (3233304033323).

The spelling of 2021202012121 in words is "two trillion, twenty-one billion, two hundred two million, twelve thousand, one hundred twenty-one".