18172517158 has 4 divisors (see below), whose sum is σ = 27258775740. Its totient is φ = 9086258578.

The previous prime is 18172517123. The next prime is 18172517159. The reversal of 18172517158 is 85171527181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 85171527181 = 13 ⋅6551655937.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18172517159) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4543129288 + ... + 4543129291.

It is an arithmetic number, because the mean of its divisors is an integer number (6814693935).

Almost surely, 2^18172517158 is an apocalyptic number.

18172517158 is a deficient number, since it is larger than the sum of its proper divisors (9086258582).

18172517158 is an equidigital number, since it uses as much as digits as its factorization.

18172517158 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9086258581.

The product of its digits is 156800, while the sum is 46.

The spelling of 18172517158 in words is "eighteen billion, one hundred seventy-two million, five hundred seventeen thousand, one hundred fifty-eight".