13991887 has 8 divisors (see below), whose sum is σ = 17220896. Its totient is φ = 11070432.

The previous prime is 13991869. The next prime is 13991897. The reversal of 13991887 is 78819931.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13991887 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13991807) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 76788 + ... + 76969.

It is an arithmetic number, because the mean of its divisors is an integer number (2152612).

Almost surely, 2^13991887 is an apocalyptic number.

13991887 is a deficient number, since it is larger than the sum of its proper divisors (3229009).

13991887 is a wasteful number, since it uses less digits than its factorization.

13991887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153777.

The product of its digits is 108864, while the sum is 46.

The square root of 13991887 is about 3740.5730844351. The cubic root of 13991887 is about 240.9676615068.

It can be divided in two parts, 13991 and 887, that added together give a triangular number (14878 = T₁₇₂).

The spelling of 13991887 in words is "thirteen million, nine hundred ninety-one thousand, eight hundred eighty-seven".