20117505555231 has 24 divisors (see below), whose sum is σ = 30898527603840. Its totient is φ = 11405199807792.

The previous prime is 20117505555221. The next prime is 20117505555349. The reversal of 20117505555231 is 13255550571102.

It is not a de Polignac number, because 20117505555231 - 2²¹ = 20117503458079 is a prime.

It is a super-2 number, since 2×20117505555231² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20117505555221) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 29358621 + ... + 30036038.

It is an arithmetic number, because the mean of its divisors is an integer number (1287438650160).

Almost surely, 2^{20117505555231} is an apocalyptic number.

20117505555231 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

20117505555231 is a deficient number, since it is larger than the sum of its proper divisors (10781022048609).

20117505555231 is an equidigital number, since it uses as much as digits as its factorization.

20117505555231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59394923 (or 59394796 counting only the distinct ones).

The product of its (nonzero) digits is 262500, while the sum is 42.

The spelling of 20117505555231 in words is "twenty trillion, one hundred seventeen billion, five hundred five million, five hundred fifty-five thousand, two hundred thirty-one".