86991031 has 8 divisors (see below), whose sum is σ = 89415360. Its totient is φ = 84590688.

The previous prime is 86991029. The next prime is 86991041. The reversal of 86991031 is 13019968.

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 86991031 - 2¹ = 86991029 is a prime.

It is a super-2 number, since 2×86991031² = 15134878948885922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (86991041) 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, 1485 + ... + 13273.

It is an arithmetic number, because the mean of its divisors is an integer number (11176920).

Almost surely, 2^86991031 is an apocalyptic number.

86991031 is a deficient number, since it is larger than the sum of its proper divisors (2424329).

86991031 is a wasteful number, since it uses less digits than its factorization.

86991031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11993.

The product of its (nonzero) digits is 11664, while the sum is 37.

The square root of 86991031 is about 9326.8982518306. The cubic root of 86991031 is about 443.0895348008.

It can be divided in two parts, 8699 and 1031, that added together give a triangular number (9730 = T₁₃₉).

The spelling of 86991031 in words is "eighty-six million, nine hundred ninety-one thousand, thirty-one".