18516 has 12 divisors (see below), whose sum is σ = 43232. Its totient is φ = 6168.

The previous prime is 18503. The next prime is 18517. The reversal of 18516 is 61581.

18516 = T₆₄ + T₆₅ + ... + T₇₁.

It is a tau number, because it is divible by the number of its divisors (12).

It is a nialpdrome in base 12.

It is a junction number, because it is equal to n+sod(n) for n = 18492 and 18501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18517) by changing a digit.

18516 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 760 + ... + 783.

2¹⁸⁵¹⁶ is an apocalyptic number.

It is an amenable number.

18516 is an abundant number, since it is smaller than the sum of its proper divisors (24716).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21616).

18516 is a wasteful number, since it uses less digits than its factorization.

18516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1550 (or 1548 counting only the distinct ones).

The product of its digits is 240, while the sum is 21.

The square root of 18516 is about 136.0735095454. The cubic root of 18516 is about 26.4554847754.

The spelling of 18516 in words is "eighteen thousand, five hundred sixteen".