688766809 has 8 divisors (see below), whose sum is σ = 719000640. Its totient is φ = 658556976.

The previous prime is 688766807. The next prime is 688766821. The reversal of 688766809 is 908667886.

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

It is not a de Polignac number, because 688766809 - 2¹ = 688766807 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (688766801) 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, 77602 + ... + 86020.

It is an arithmetic number, because the mean of its divisors is an integer number (89875080).

Almost surely, 2^688766809 is an apocalyptic number.

It is an amenable number.

688766809 is a deficient number, since it is larger than the sum of its proper divisors (30233831).

688766809 is a wasteful number, since it uses less digits than its factorization.

688766809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11999.

The product of its (nonzero) digits is 6967296, while the sum is 58.

The square root of 688766809 is about 26244.3671861221. The cubic root of 688766809 is about 883.1288453992.

The spelling of 688766809 in words is "six hundred eighty-eight million, seven hundred sixty-six thousand, eight hundred nine".