86815981 has 8 divisors (see below), whose sum is σ = 99437184. Its totient is φ = 74249520.

The previous prime is 86815973. The next prime is 86816017. The reversal of 86815981 is 18951868.

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 86815981 - 2³ = 86815973 is a prime.

It is a super-2 number, since 2×86815981² = 15074029113984722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (86815951) 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, 10225 + ... + 16678.

It is an arithmetic number, because the mean of its divisors is an integer number (12429648).

Almost surely, 2^86815981 is an apocalyptic number.

It is an amenable number.

86815981 is a deficient number, since it is larger than the sum of its proper divisors (12621203).

86815981 is a wasteful number, since it uses less digits than its factorization.

86815981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27371.

The product of its digits is 138240, while the sum is 46.

The square root of 86815981 is about 9317.5093775107. The cubic root of 86815981 is about 442.7921290171.

The spelling of 86815981 in words is "eighty-six million, eight hundred fifteen thousand, nine hundred eighty-one".