13987 has 4 divisors (see below), whose sum is σ = 14256.
Its totient is φ = 13720.
The previous prime is 13967. The next prime is 13997. The reversal of 13987 is 78931.
It can be divided in two parts, 13 and 987, that added together give a cube (1000 = 103).
It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78931 = 17 ⋅4643.
It is a cyclic number.
It is not a de Polignac number, because 13987 - 27 = 13859 is a prime.
It is a Duffinian number.
13987 is an undulating number in base 14.
It is a nialpdrome in base 7.
It is not an unprimeable number, because it can be changed into a prime (13907) 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, 28 + ... + 169.
It is an arithmetic number, because the mean of its divisors is an integer number (3564).
213987 is an apocalyptic number.
13987 is a deficient number, since it is larger than the sum of its proper divisors (269).
13987 is an equidigital number, since it uses as much as digits as its factorization.
13987 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 268.
The product of its digits is 1512, while the sum is 28.
The square root of 13987 is about 118.2666478767.
The cubic root of 13987 is about 24.0939603674.
The spelling of 13987 in words is "thirteen thousand, nine hundred eighty-seven".