659989 has 4 divisors (see below), whose sum is σ = 720000. Its totient is φ = 599980.

The previous prime is 659983. The next prime is 659999. The reversal of 659989 is 989956.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 659989 - 2¹⁹ = 135701 is a prime.

It is a Duffinian number.

659989 is a lucky number.

It is a congruent number.

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

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 3 ways as a sum of consecutive naturals, for example, 29989 + ... + 30010.

It is an arithmetic number, because the mean of its divisors is an integer number (180000).

2⁶⁵⁹⁹⁸⁹ is an apocalyptic number.

It is an amenable number.

659989 is a deficient number, since it is larger than the sum of its proper divisors (60011).

659989 is a wasteful number, since it uses less digits than its factorization.

659989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60010.

The product of its digits is 174960, while the sum is 46.

The square root of 659989 is about 812.3970704034. The cubic root of 659989 is about 87.0653932097.

It can be divided in two parts, 6 and 59989, that added together give a palindrome (59995).

The spelling of 659989 in words is "six hundred fifty-nine thousand, nine hundred eighty-nine".