18315 has 24 divisors (see below), whose sum is σ = 35568. Its totient is φ = 8640.

The previous prime is 18313. The next prime is 18329. The reversal of 18315 is 51381.

Added to its reverse (51381) it gives a square (69696 = 264²).

It is a happy number.

18315 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 18315 - 2¹ = 18313 is a prime.

18315 is a lucky number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18311) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 477 + ... + 513.

It is an arithmetic number, because the mean of its divisors is an integer number (1482).

2¹⁸³¹⁵ is an apocalyptic number.

18315 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

18315 is a deficient number, since it is larger than the sum of its proper divisors (17253).

18315 is a wasteful number, since it uses less digits than its factorization.

18315 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59 (or 56 counting only the distinct ones).

The product of its digits is 120, while the sum is 18.

The square root of 18315 is about 135.3329228237. The cubic root of 18315 is about 26.3594073136.

Adding to 18315 its reverse (51381), we get a palindrome (69696).

It can be divided in two parts, 18 and 315, that added together give a palindrome (333).

The spelling of 18315 in words is "eighteen thousand, three hundred fifteen".