13999987 has 4 divisors (see below), whose sum is σ = 14130936. Its totient is φ = 13869040.

The previous prime is 13999981. The next prime is 14000029. The reversal of 13999987 is 78999931.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78999931 = 173 ⋅456647.

It is a cyclic number.

It is not a de Polignac number, because 13999987 - 2¹¹ = 13997939 is a prime.

It is a pancake number, because a pancake can be divided into 13999987 parts by 5291 straight cuts.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13999981) 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, 65314 + ... + 65527.

It is an arithmetic number, because the mean of its divisors is an integer number (3532734).

Almost surely, 2^13999987 is an apocalyptic number.

13999987 is a deficient number, since it is larger than the sum of its proper divisors (130949).

13999987 is a wasteful number, since it uses less digits than its factorization.

13999987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130948.

The product of its digits is 1102248, while the sum is 55.

The square root of 13999987 is about 3741.6556495755. The cubic root of 13999987 is about 241.0141518179.

It can be divided in two parts, 13 and 999987, that added together give a 6-th power (1000000 = 10⁶).

The spelling of 13999987 in words is "thirteen million, nine hundred ninety-nine thousand, nine hundred eighty-seven".