659988 has 72 divisors (see below), whose sum is σ = 1997632. Its totient is φ = 186624.

The previous prime is 659983. The next prime is 659999. The reversal of 659988 is 889956.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (659983) by changing a digit.

659988 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 23 ways as a sum of consecutive naturals, for example, 6756 + ... + 6852.

2⁶⁵⁹⁹⁸⁸ 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 659988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (998816).

659988 is an abundant number, since it is smaller than the sum of its proper divisors (1337644).

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

659988 is a wasteful number, since it uses less digits than its factorization.

659988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123 (or 109 counting only the distinct ones).

The product of its digits is 155520, while the sum is 45.

The square root of 659988 is about 812.3964549406. The cubic root of 659988 is about 87.0653492366.

The spelling of 659988 in words is "six hundred fifty-nine thousand, nine hundred eighty-eight".