679643 has 4 divisors (see below), whose sum is σ = 719640. Its totient is φ = 639648.

The previous prime is 679639. The next prime is 679669. The reversal of 679643 is 346976.

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

It is a cyclic number.

It is not a de Polignac number, because 679643 - 2² = 679639 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (679603) 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, 19973 + ... + 20006.

It is an arithmetic number, because the mean of its divisors is an integer number (179910).

2⁶⁷⁹⁶⁴³ is an apocalyptic number.

679643 is a deficient number, since it is larger than the sum of its proper divisors (39997).

679643 is a wasteful number, since it uses less digits than its factorization.

679643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39996.

The product of its digits is 27216, while the sum is 35.

The square root of 679643 is about 824.4046336600. The cubic root of 679643 is about 87.9212018455.

The spelling of 679643 in words is "six hundred seventy-nine thousand, six hundred forty-three".