685679989 has 8 divisors (see below), whose sum is σ = 726306048. Its totient is φ = 645086400.

The previous prime is 685679963. The next prime is 685680007. The reversal of 685679989 is 989976586.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-685679989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (685679909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 45564 + ... + 58714.

It is an arithmetic number, because the mean of its divisors is an integer number (90788256).

Almost surely, 2^685679989 is an apocalyptic number.

It is an amenable number.

685679989 is a deficient number, since it is larger than the sum of its proper divisors (40626059).

685679989 is a wasteful number, since it uses less digits than its factorization.

685679989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16235.

The product of its digits is 58786560, while the sum is 67.

The square root of 685679989 is about 26185.4919564250. The cubic root of 685679989 is about 881.8075746184.

The spelling of 685679989 in words is "six hundred eighty-five million, six hundred seventy-nine thousand, nine hundred eighty-nine".