18138291 has 8 divisors (see below), whose sum is σ = 24205200. Its totient is φ = 12081792.

The previous prime is 18138247. The next prime is 18138343. The reversal of 18138291 is 19283181.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18138291 - 2⁶ = 18138227 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18138221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3535 + ... + 6983.

It is an arithmetic number, because the mean of its divisors is an integer number (3025650).

Almost surely, 2^18138291 is an apocalyptic number.

18138291 is a deficient number, since it is larger than the sum of its proper divisors (6066909).

18138291 is a wasteful number, since it uses less digits than its factorization.

18138291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5205.

The product of its digits is 3456, while the sum is 33.

The square root of 18138291 is about 4258.9072542144. The cubic root of 18138291 is about 262.7435852346.

The spelling of 18138291 in words is "eighteen million, one hundred thirty-eight thousand, two hundred ninety-one".