87991113 has 24 divisors (see below), whose sum is σ = 140885760. Its totient is φ = 48656160.

The previous prime is 87991063. The next prime is 87991139. The reversal of 87991113 is 31119978.

It is not a de Polignac number, because 87991113 - 2⁹ = 87990601 is a prime.

It is not an unprimeable number, because it can be changed into a prime (87991153) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5098 + ... + 14211.

It is an arithmetic number, because the mean of its divisors is an integer number (5870240).

Almost surely, 2^87991113 is an apocalyptic number.

It is an amenable number.

87991113 is a deficient number, since it is larger than the sum of its proper divisors (52894647).

87991113 is a wasteful number, since it uses less digits than its factorization.

87991113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19357 (or 19350 counting only the distinct ones).

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

The square root of 87991113 is about 9380.3578289957. The cubic root of 87991113 is about 444.7810444954.

The spelling of 87991113 in words is "eighty-seven million, nine hundred ninety-one thousand, one hundred thirteen".