86815720 has 16 divisors (see below), whose sum is σ = 195335460. Its totient is φ = 34726272.

The previous prime is 86815711. The next prime is 86815783. The reversal of 86815720 is 2751868.

It can be written as a sum of positive squares in 2 ways, for example, as 76842756 + 9972964 = 8766^2 + 3158^2 .

It is a super-3 number, since 3×86815720³ (a number of 25 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 86815720.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1085157 + ... + 1085236.

Almost surely, 2^86815720 is an apocalyptic number.

It is an amenable number.

86815720 is an abundant number, since it is smaller than the sum of its proper divisors (108519740).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

86815720 is a wasteful number, since it uses less digits than its factorization.

86815720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2170404 (or 2170400 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 37.

The square root of 86815720 is about 9317.4953716114. The cubic root of 86815720 is about 442.7916852860.

The spelling of 86815720 in words is "eighty-six million, eight hundred fifteen thousand, seven hundred twenty".