18172267173 has 6 divisors (see below), whose sum is σ = 26248830374. Its totient is φ = 12114844776.

The previous prime is 18172267163. The next prime is 18172267193. The reversal of 18172267173 is 37176227181.

It can be written as a sum of positive squares in only one way, i.e., 16512764004 + 1659503169 = 128502^2 + 40737^2 .

It is not a de Polignac number, because 18172267173 - 2⁹ = 18172266661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18172267103) 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 in 5 ways as a sum of consecutive naturals, for example, 1009570390 + ... + 1009570407.

Almost surely, 2^18172267173 is an apocalyptic number.

It is an amenable number.

18172267173 is a deficient number, since it is larger than the sum of its proper divisors (8076563201).

18172267173 is a wasteful number, since it uses less digits than its factorization.

18172267173 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2019140803 (or 2019140800 counting only the distinct ones).

The product of its digits is 197568, while the sum is 45.

The spelling of 18172267173 in words is "eighteen billion, one hundred seventy-two million, two hundred sixty-seven thousand, one hundred seventy-three".