20561565059105 has 16 divisors (see below), whose sum is σ = 28199932959360. Its totient is φ = 14098751315712.

The previous prime is 20561565059089. The next prime is 20561565059131. The reversal of 20561565059105 is 50195056516502.

It is not a de Polignac number, because 20561565059105 - 2⁴ = 20561565059089 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11833400 + ... + 13459289.

It is an arithmetic number, because the mean of its divisors is an integer number (1762495809960).

Almost surely, 2^{20561565059105} is an apocalyptic number.

It is an amenable number.

20561565059105 is a deficient number, since it is larger than the sum of its proper divisors (7638367900255).

20561565059105 is a wasteful number, since it uses less digits than its factorization.

20561565059105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25315928.

The product of its (nonzero) digits is 2025000, while the sum is 50.

The spelling of 20561565059105 in words is "twenty trillion, five hundred sixty-one billion, five hundred sixty-five million, fifty-nine thousand, one hundred five".