20311220122021 has 2 divisors, whose sum is σ = 20311220122022. Its totient is φ = 20311220122020.

The previous prime is 20311220121979. The next prime is 20311220122133. The reversal of 20311220122021 is 12022102211302.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17574213849921 + 2737006272100 = 4192161^2 + 1654390^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20311220122021 is a prime.

It is a super-2 number, since 2×20311220122021² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20311220122021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20311220152021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10155610061010 + 10155610061011.

It is an arithmetic number, because the mean of its divisors is an integer number (10155610061011).

Almost surely, 2^{20311220122021} is an apocalyptic number.

It is an amenable number.

20311220122021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20311220122021 is an equidigital number, since it uses as much as digits as its factorization.

20311220122021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 192, while the sum is 19.

Adding to 20311220122021 its reverse (12022102211302), we get a palindrome (32333322333323).

The spelling of 20311220122021 in words is "twenty trillion, three hundred eleven billion, two hundred twenty million, one hundred twenty-two thousand, twenty-one".