15856 has 10 divisors (see below), whose sum is σ = 30752. Its totient is φ = 7920.

The previous prime is 15823. The next prime is 15859. The reversal of 15856 is 65851.

It is a plaindrome in base 9.

It is a self number, because there is not a number n which added to its sum of digits gives 15856.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15859) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 480 + ... + 511.

2¹⁵⁸⁵⁶ is an apocalyptic number.

15856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

15856 is a deficient number, since it is larger than the sum of its proper divisors (14896).

15856 is an equidigital number, since it uses as much as digits as its factorization.

15856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 999 (or 993 counting only the distinct ones).

The product of its digits is 1200, while the sum is 25.

The square root of 15856 is about 125.9206099096. The cubic root of 15856 is about 25.1225978083.

The spelling of 15856 in words is "fifteen thousand, eight hundred fifty-six".