87999931 has 4 divisors (see below), whose sum is σ = 88582864. Its totient is φ = 87417000.

The previous prime is 87999929. The next prime is 87999941. The reversal of 87999931 is 13999978.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13999978 = 2 ⋅6999989.

It is a cyclic number.

It is not a de Polignac number, because 87999931 - 2¹ = 87999929 is a prime.

It is a super-2 number, since 2×87999931² = 15487975712009522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (87999941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 291240 + ... + 291541.

It is an arithmetic number, because the mean of its divisors is an integer number (22145716).

Almost surely, 2^87999931 is an apocalyptic number.

87999931 is a deficient number, since it is larger than the sum of its proper divisors (582933).

87999931 is a wasteful number, since it uses less digits than its factorization.

87999931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 582932.

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

The square root of 87999931 is about 9380.8278419338. The cubic root of 87999931 is about 444.7959018603.

The spelling of 87999931 in words is "eighty-seven million, nine hundred ninety-nine thousand, nine hundred thirty-one".