18157181 has 16 divisors (see below), whose sum is σ = 21373440. Its totient is φ = 15102720.

The previous prime is 18157177. The next prime is 18157187. The reversal of 18157181 is 18175181.

It is a cyclic number.

It is not a de Polignac number, because 18157181 - 2² = 18157177 is a prime.

It is a super-2 number, since 2×18157181² = 659366443733522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18157187) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 75221 + ... + 75461.

It is an arithmetic number, because the mean of its divisors is an integer number (1335840).

Almost surely, 2^18157181 is an apocalyptic number.

It is an amenable number.

18157181 is a deficient number, since it is larger than the sum of its proper divisors (3216259).

18157181 is a wasteful number, since it uses less digits than its factorization.

18157181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 524.

The product of its digits is 2240, while the sum is 32.

The square root of 18157181 is about 4261.1243821320. The cubic root of 18157181 is about 262.8347644302.

The spelling of 18157181 in words is "eighteen million, one hundred fifty-seven thousand, one hundred eighty-one".