688769 has 4 divisors (see below), whose sum is σ = 725040. Its totient is φ = 652500.

The previous prime is 688763. The next prime is 688777. The reversal of 688769 is 967886.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-688769 is a prime.

It is a super-2 number, since 2×688769² = 948805470722, which contains 22 as substring.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 688769.

It is not an unprimeable number, because it can be changed into a prime (688763) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18107 + ... + 18144.

It is an arithmetic number, because the mean of its divisors is an integer number (181260).

2⁶⁸⁸⁷⁶⁹ is an apocalyptic number.

It is an amenable number.

688769 is a deficient number, since it is larger than the sum of its proper divisors (36271).

688769 is a wasteful number, since it uses less digits than its factorization.

688769 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36270.

The product of its digits is 145152, while the sum is 44.

The square root of 688769 is about 829.9210805854. The cubic root of 688769 is about 88.3129781823.

The spelling of 688769 in words is "six hundred eighty-eight thousand, seven hundred sixty-nine".