18738181 has 12 divisors (see below), whose sum is σ = 23539936. Its totient is φ = 14600520.

The previous prime is 18738179. The next prime is 18738197. The reversal of 18738181 is 18183781.

It is not a de Polignac number, because 18738181 - 2¹ = 18738179 is a prime.

It is a super-2 number, since 2×18738181² = 702238854377522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 18738181.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18738121) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10215 + ... + 11908.

Almost surely, 2^18738181 is an apocalyptic number.

18738181 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18738181 is a deficient number, since it is larger than the sum of its proper divisors (4801755).

18738181 is a wasteful number, since it uses less digits than its factorization.

18738181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22152 (or 22141 counting only the distinct ones).

The product of its digits is 10752, while the sum is 37.

The square root of 18738181 is about 4328.7620632232. The cubic root of 18738181 is about 265.6088102889.

The spelling of 18738181 in words is "eighteen million, seven hundred thirty-eight thousand, one hundred eighty-one".