679989 has 4 divisors (see below), whose sum is σ = 906656. Its totient is φ = 453324.

The previous prime is 679981. The next prime is 679993. The reversal of 679989 is 989976.

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 not a de Polignac number, because 679989 - 2³ = 679981 is a prime.

It is a D-number.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (679981) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 113329 + ... + 113334.

It is an arithmetic number, because the mean of its divisors is an integer number (226664).

2⁶⁷⁹⁹⁸⁹ is an apocalyptic number.

It is an amenable number.

679989 is a deficient number, since it is larger than the sum of its proper divisors (226667).

679989 is a wasteful number, since it uses less digits than its factorization.

679989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226666.

The product of its digits is 244944, while the sum is 48.

The square root of 679989 is about 824.6144553669. The cubic root of 679989 is about 87.9361192727.

The spelling of 679989 in words is "six hundred seventy-nine thousand, nine hundred eighty-nine".