15987 has 6 divisors (see below), whose sum is σ = 21612.
Its totient is φ = 10512.
The previous prime is 15973. The next prime is 15991. The reversal of 15987 is 78951.
15987 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.
It is not a de Polignac number, because 15987 - 24 = 15971 is a prime.
It is a zygodrome in base 2.
It is not an unprimeable number, because it can be changed into a prime (15907) by changing a digit.
It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 183 + ... + 255.
It is an arithmetic number, because the mean of its divisors is an integer number (3602).
215987 is an apocalyptic number.
15987 is a deficient number, since it is larger than the sum of its proper divisors (5625).
15987 is an frugal number, since it uses more digits than its factorization.
15987 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 149 (or 76 counting only the distinct ones).
The product of its digits is 2520, while the sum is 30.
The square root of 15987 is about 126.4397089525.
The cubic root of 15987 is about 25.1915945764.
The spelling of 15987 in words is "fifteen thousand, nine hundred eighty-seven".