509988 has 12 divisors (see below), whose sum is σ = 1190000. Its totient is φ = 169992.

The previous prime is 509963. The next prime is 509989. The reversal of 509988 is 889905.

It is a tau number, because it is divible by the number of its divisors (12).

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 509988.

It is not an unprimeable number, because it can be changed into a prime (509989) by changing a digit.

509988 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 3 ways as a sum of consecutive naturals, for example, 21238 + ... + 21261.

2⁵⁰⁹⁹⁸⁸ is an apocalyptic number.

It is an amenable number.

509988 is an abundant number, since it is smaller than the sum of its proper divisors (680012).

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

509988 is a wasteful number, since it uses less digits than its factorization.

509988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42506 (or 42504 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 39.

The square root of 509988 is about 714.1344411244. The cubic root of 509988 is about 79.8950707667.

The spelling of 509988 in words is "five hundred nine thousand, nine hundred eighty-eight".