86640 has 60 divisors (see below), whose sum is σ = 283464. Its totient is φ = 21888.

The previous prime is 86629. The next prime is 86677. The reversal of 86640 is 4668.

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a nialpdrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 86640.

It is a congruent number.

It is an unprimeable number.

86640 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4551 + ... + 4569.

2⁸⁶⁶⁴⁰ is an apocalyptic number.

86640 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 86640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (141732).

86640 is an abundant number, since it is smaller than the sum of its proper divisors (196824).

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

86640 is a wasteful number, since it uses less digits than its factorization.

86640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54 (or 29 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 86640 is about 294.3467343118. The cubic root of 86640 is about 44.2492738238.

The spelling of 86640 in words is "eighty-six thousand, six hundred forty".