679661 has 4 divisors (see below), whose sum is σ = 682812. Its totient is φ = 676512.

The previous prime is 679639. The next prime is 679669. The reversal of 679661 is 166976.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 481636 + 198025 = 694^2 + 445^2 .

It is a cyclic number.

It is not a de Polignac number, because 679661 - 2⁶ = 679597 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 679661.

It is not an unprimeable number, because it can be changed into a prime (679669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1226 + ... + 1691.

It is an arithmetic number, because the mean of its divisors is an integer number (170703).

2⁶⁷⁹⁶⁶¹ is an apocalyptic number.

It is an amenable number.

679661 is a deficient number, since it is larger than the sum of its proper divisors (3151).

679661 is a wasteful number, since it uses less digits than its factorization.

679661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3150.

The product of its digits is 13608, while the sum is 35.

The square root of 679661 is about 824.4155505569. The cubic root of 679661 is about 87.9219780214.

The spelling of 679661 in words is "six hundred seventy-nine thousand, six hundred sixty-one".