20117510605517 has 8 divisors (see below), whose sum is σ = 21793206757560. Its totient is φ = 18570009787680.

The previous prime is 20117510605501. The next prime is 20117510605547. The reversal of 20117510605517 is 71550601571102.

It can be written as a sum of positive squares in 4 ways, for example, as 4604775223876 + 15512735381641 = 2145874^2 + 3938621^2 .

It is not a de Polignac number, because 20117510605517 - 2⁴ = 20117510605501 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20117510605547) 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 in 7 ways as a sum of consecutive naturals, for example, 4578402584 + ... + 4578406977.

It is an arithmetic number, because the mean of its divisors is an integer number (2724150844695).

Almost surely, 2^{20117510605517} is an apocalyptic number.

It is an amenable number.

20117510605517 is a deficient number, since it is larger than the sum of its proper divisors (1675696152043).

20117510605517 is an frugal number, since it uses more digits than its factorization.

20117510605517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9156809600 (or 9156809574 counting only the distinct ones).

The product of its (nonzero) digits is 73500, while the sum is 41.

The spelling of 20117510605517 in words is "twenty trillion, one hundred seventeen billion, five hundred ten million, six hundred five thousand, five hundred seventeen".