659664 has 50 divisors (see below), whose sum is σ = 1913010. Its totient is φ = 219456.

The previous prime is 659657. The next prime is 659669. The reversal of 659664 is 466956.

It is a happy number.

659664 is a `hidden beast` number, since 6 + 596 + 64 = 666.

It can be written as a sum of positive squares in only one way, i.e., 627264 + 32400 = 792^2 + 180^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (659669) by changing a digit.

659664 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 1042 + ... + 1550.

2⁶⁵⁹⁶⁶⁴ 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 659664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (956505).

659664 is an abundant number, since it is smaller than the sum of its proper divisors (1253346).

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

659664 is a wasteful number, since it uses less digits than its factorization.

659664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 529 (or 514 counting only the distinct ones).

The product of its digits is 38880, while the sum is 36.

The square root of 659664 is about 812.1970204329. The cubic root of 659664 is about 87.0510995883.

The spelling of 659664 in words is "six hundred fifty-nine thousand, six hundred sixty-four".