20517430975 has 6 divisors (see below), whose sum is σ = 25441614440. Its totient is φ = 16413944760.

The previous prime is 20517430961. The next prime is 20517430993. The reversal of 20517430975 is 57903471502.

It is not a de Polignac number, because 20517430975 - 2⁵ = 20517430943 is a prime.

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, 410348595 + ... + 410348644.

Almost surely, 2^20517430975 is an apocalyptic number.

20517430975 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

20517430975 is a deficient number, since it is larger than the sum of its proper divisors (4924183465).

20517430975 is an equidigital number, since it uses as much as digits as its factorization.

20517430975 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 820697249 (or 820697244 counting only the distinct ones).

The product of its (nonzero) digits is 264600, while the sum is 43.

The spelling of 20517430975 in words is "twenty billion, five hundred seventeen million, four hundred thirty thousand, nine hundred seventy-five".