15816 has 16 divisors (see below), whose sum is σ = 39600. Its totient is φ = 5264.

The previous prime is 15809. The next prime is 15817. The reversal of 15816 is 61851.

It is a junction number, because it is equal to n+sod(n) for n = 15792 and 15801.

It is not an unprimeable number, because it can be changed into a prime (15817) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 306 + ... + 353.

It is an arithmetic number, because the mean of its divisors is an integer number (2475).

2¹⁵⁸¹⁶ is an apocalyptic number.

It is an amenable number.

15816 is an abundant number, since it is smaller than the sum of its proper divisors (23784).

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 (19800).

15816 is a wasteful number, since it uses less digits than its factorization.

15816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 668 (or 664 counting only the distinct ones).

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

The square root of 15816 is about 125.7616793781. The cubic root of 15816 is about 25.1014543900.

Subtracting from 15816 its product of digits (240), we obtain a triangular number (15576 = T₁₇₆).

The spelling of 15816 in words is "fifteen thousand, eight hundred sixteen".