20105717525 has 6 divisors (see below), whose sum is σ = 24931089762. Its totient is φ = 16084574000.

The previous prime is 20105717509. The next prime is 20105717531. The reversal of 20105717525 is 52571750102.

It can be written as a sum of positive squares in 3 ways, for example, as 3819363601 + 16286353924 = 61801^2 + 127618^2 .

It is not a de Polignac number, because 20105717525 - 2⁴ = 20105717509 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 402114326 + ... + 402114375.

It is an arithmetic number, because the mean of its divisors is an integer number (4155181627).

Almost surely, 2^20105717525 is an apocalyptic number.

20105717525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20105717525 is a deficient number, since it is larger than the sum of its proper divisors (4825372237).

20105717525 is an equidigital number, since it uses as much as digits as its factorization.

20105717525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 804228711 (or 804228706 counting only the distinct ones).

The product of its (nonzero) digits is 24500, while the sum is 35.

The spelling of 20105717525 in words is "twenty billion, one hundred five million, seven hundred seventeen thousand, five hundred twenty-five".