18915 has 16 divisors (see below), whose sum is σ = 32928. Its totient is φ = 9216.

The previous prime is 18913. The next prime is 18917. The reversal of 18915 is 51981.

18915 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

18915 is a nontrivial binomial coefficient, being equal to C(195, 2).

It is an interprime number because it is at equal distance from previous prime (18913) and next prime (18917).

It is not a de Polignac number, because 18915 - 2¹ = 18913 is a prime.

It is a D-number.

18915 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (18911) 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, 147 + ... + 243.

It is an arithmetic number, because the mean of its divisors is an integer number (2058).

2¹⁸⁹¹⁵ is an apocalyptic number.

18915 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

18915 is the 194-th triangular number.

18915 is a deficient number, since it is larger than the sum of its proper divisors (14013).

18915 is a wasteful number, since it uses less digits than its factorization.

18915 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118.

The product of its digits is 360, while the sum is 24.

The square root of 18915 is about 137.5318145012. The cubic root of 18915 is about 26.6441650460.

The spelling of 18915 in words is "eighteen thousand, nine hundred fifteen".