20117557222161 has 16 divisors (see below), whose sum is σ = 31280944176000. Its totient is φ = 11495746983504.

The previous prime is 20117557222153. The next prime is 20117557222163. The reversal of 20117557222161 is 16122275571102.

It is not a de Polignac number, because 20117557222161 - 2³ = 20117557222153 is a prime.

It is a super-2 number, since 2×20117557222161² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20117557222163) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9775294026 + ... + 9775296083.

It is an arithmetic number, because the mean of its divisors is an integer number (1955059011000).

Almost surely, 2^{20117557222161} is an apocalyptic number.

20117557222161 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20117557222161 is a deficient number, since it is larger than the sum of its proper divisors (11163386953839).

20117557222161 is an equidigital number, since it uses as much as digits as its factorization.

20117557222161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19550590133 (or 19550590119 counting only the distinct ones).

The product of its (nonzero) digits is 117600, while the sum is 42.

The spelling of 20117557222161 in words is "twenty trillion, one hundred seventeen billion, five hundred fifty-seven million, two hundred twenty-two thousand, one hundred sixty-one".