202021131121021 has 4 divisors (see below), whose sum is σ = 202028066545500. Its totient is φ = 202014195696544.

The previous prime is 202021131121009. The next prime is 202021131121031. The reversal of 202021131121021 is 120121131120202.

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 145810334288025 + 56210796832996 = 12075195^2 + 7497386^2 .

It is a cyclic number.

It is not a de Polignac number, because 202021131121021 - 2⁹ = 202021131120509 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 202021131121021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (202021131121031) 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, 3467668546 + ... + 3467726803.

It is an arithmetic number, because the mean of its divisors is an integer number (50507016636375).

Almost surely, 2^{202021131121021} is an apocalyptic number.

It is an amenable number.

202021131121021 is a deficient number, since it is larger than the sum of its proper divisors (6935424479).

202021131121021 is an equidigital number, since it uses as much as digits as its factorization.

202021131121021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6935424478.

The product of its (nonzero) digits is 96, while the sum is 19.

Adding to 202021131121021 its reverse (120121131120202), we get a palindrome (322142262241223).

The spelling of 202021131121021 in words is "two hundred two trillion, twenty-one billion, one hundred thirty-one million, one hundred twenty-one thousand, twenty-one".