18291 has 16 divisors (see below), whose sum is σ = 30464. Its totient is φ = 9504.

The previous prime is 18289. The next prime is 18301. The reversal of 18291 is 19281.

18291 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 18291 - 2¹ = 18289 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a nialpdrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (18211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 240 + ... + 306.

It is an arithmetic number, because the mean of its divisors is an integer number (1904).

2¹⁸²⁹¹ is an apocalyptic number.

18291 is a deficient number, since it is larger than the sum of its proper divisors (12173).

18291 is a wasteful number, since it uses less digits than its factorization.

It is an anagram of its base 11 representation: 18291 = (12819)₁₁.

18291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90.

The product of its digits is 144, while the sum is 21.

The square root of 18291 is about 135.2442235365. The cubic root of 18291 is about 26.3478884800.

Subtracting 18291 from its reverse (19281), we obtain a triangular number (990 = T₄₄).

It can be divided in two parts, 1829 and 1, that added together give a triangular number (1830 = T₆₀).

The spelling of 18291 in words is "eighteen thousand, two hundred ninety-one".