2021122120121 has 4 divisors (see below), whose sum is σ = 2176593052452. Its totient is φ = 1865651187792.

The previous prime is 2021122120117. The next prime is 2021122120159. The reversal of 2021122120121 is 1210212211202.

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 723035599225 + 1298086520896 = 850315^2 + 1139336^2 .

It is a cyclic number.

It is not a de Polignac number, because 2021122120121 - 2² = 2021122120117 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2021122120121.

It is not an unprimeable number, because it can be changed into a prime (2021122120421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 77735466146 + ... + 77735466171.

It is an arithmetic number, because the mean of its divisors is an integer number (544148263113).

Almost surely, 2^{2021122120121} is an apocalyptic number.

It is an amenable number.

2021122120121 is a deficient number, since it is larger than the sum of its proper divisors (155470932331).

2021122120121 is a wasteful number, since it uses less digits than its factorization.

2021122120121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155470932330.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 2021122120121 its reverse (1210212211202), we get a palindrome (3231334331323).

The spelling of 2021122120121 in words is "two trillion, twenty-one billion, one hundred twenty-two million, one hundred twenty thousand, one hundred twenty-one".