20563042555021 has 2 divisors, whose sum is σ = 20563042555022. Its totient is φ = 20563042555020.

The previous prime is 20563042554991. The next prime is 20563042555031. The reversal of 20563042555021 is 12055524036502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16104128870025 + 4458913684996 = 4012995^2 + 2111614^2 .

It is a cyclic number.

It is not a de Polignac number, because 20563042555021 - 2¹⁷ = 20563042423949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20563042555031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10281521277510 + 10281521277511.

It is an arithmetic number, because the mean of its divisors is an integer number (10281521277511).

Almost surely, 2^{20563042555021} is an apocalyptic number.

It is an amenable number.

20563042555021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20563042555021 is an equidigital number, since it uses as much as digits as its factorization.

20563042555021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 360000, while the sum is 40.

The spelling of 20563042555021 in words is "twenty trillion, five hundred sixty-three billion, forty-two million, five hundred fifty-five thousand, twenty-one".