679887709 has 4 divisors (see below), whose sum is σ = 682805916. Its totient is φ = 676969504.

The previous prime is 679887701. The next prime is 679887731. The reversal of 679887709 is 907788976.

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 44595684 + 635292025 = 6678^2 + 25205^2 .

It is a cyclic number.

It is not a de Polignac number, because 679887709 - 2³ = 679887701 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 (679887701) 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, 1458754 + ... + 1459219.

It is an arithmetic number, because the mean of its divisors is an integer number (170701479).

Almost surely, 2^679887709 is an apocalyptic number.

It is an amenable number.

679887709 is a deficient number, since it is larger than the sum of its proper divisors (2918207).

679887709 is a wasteful number, since it uses less digits than its factorization.

679887709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2918206.

The product of its (nonzero) digits is 10668672, while the sum is 61.

The square root of 679887709 is about 26074.6564502775. The cubic root of 679887709 is about 879.3175274140.

The spelling of 679887709 in words is "six hundred seventy-nine million, eight hundred eighty-seven thousand, seven hundred nine".