20343664256021 has 2 divisors, whose sum is σ = 20343664256022. Its totient is φ = 20343664256020.

The previous prime is 20343664255997. The next prime is 20343664256059. The reversal of 20343664256021 is 12065246634302.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19938100344100 + 405563911921 = 4465210^2 + 636839^2 .

It is a cyclic number.

It is not a de Polignac number, because 20343664256021 - 2¹⁴ = 20343664239637 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20343664256521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10171832128010 + 10171832128011.

It is an arithmetic number, because the mean of its divisors is an integer number (10171832128011).

Almost surely, 2^{20343664256021} is an apocalyptic number.

It is an amenable number.

20343664256021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20343664256021 is an equidigital number, since it uses as much as digits as its factorization.

20343664256021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1244160, while the sum is 44.

The spelling of 20343664256021 in words is "twenty trillion, three hundred forty-three billion, six hundred sixty-four million, two hundred fifty-six thousand, twenty-one".