13191987 has 8 divisors (see below), whose sum is σ = 17887680. Its totient is φ = 8645480.

The previous prime is 13191979. The next prime is 13191991. The reversal of 13191987 is 78919131.

13191987 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 13191987 - 2³ = 13191979 is a prime.

It is not an unprimeable number, because it can be changed into a prime (13191907) 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, 37089 + ... + 37442.

It is an arithmetic number, because the mean of its divisors is an integer number (2235960).

Almost surely, 2^13191987 is an apocalyptic number.

13191987 is a deficient number, since it is larger than the sum of its proper divisors (4695693).

13191987 is an equidigital number, since it uses as much as digits as its factorization.

13191987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74593.

The product of its digits is 13608, while the sum is 39.

The square root of 13191987 is about 3632.0775046797. The cubic root of 13191987 is about 236.2853187588.

The spelling of 13191987 in words is "thirteen million, one hundred ninety-one thousand, nine hundred eighty-seven".