13666987 has 4 divisors (see below), whose sum is σ = 13854280. Its totient is φ = 13479696.

The previous prime is 13666979. The next prime is 13666999. The reversal of 13666987 is 78966631.

13666987 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 13666987 - 2³ = 13666979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13666927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 93537 + ... + 93682.

It is an arithmetic number, because the mean of its divisors is an integer number (3463570).

Almost surely, 2^13666987 is an apocalyptic number.

13666987 is a deficient number, since it is larger than the sum of its proper divisors (187293).

13666987 is an equidigital number, since it uses as much as digits as its factorization.

13666987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 187292.

The product of its digits is 326592, while the sum is 46.

The square root of 13666987 is about 3696.8888271085. Note that the first 4 decimals coincide. The cubic root of 13666987 is about 239.0878979695.

The spelling of 13666987 in words is "thirteen million, six hundred sixty-six thousand, nine hundred eighty-seven".