83640 has 64 divisors (see below), whose sum is σ = 272160. Its totient is φ = 20480.

The previous prime is 83639. The next prime is 83641. The reversal of 83640 is 4638.

83640 is nontrivially palindromic in base 7.

It is an interprime number because it is at equal distance from previous prime (83639) and next prime (83641).

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (83641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2020 + ... + 2060.

2⁸³⁶⁴⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 83640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (136080).

83640 is an abundant number, since it is smaller than the sum of its proper divisors (188520).

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

83640 is a wasteful number, since it uses less digits than its factorization.

83640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72 (or 68 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 83640 is about 289.2058090703. The cubic root of 83640 is about 43.7325372484.

The spelling of 83640 in words is "eighty-three thousand, six hundred forty".