688969313 has 4 divisors (see below), whose sum is σ = 701968788. Its totient is φ = 675969840.

The previous prime is 688969297. The next prime is 688969331. The reversal of 688969313 is 313969886.

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 400920529 + 288048784 = 20023^2 + 16972^2 .

It is a cyclic number.

It is not a de Polignac number, because 688969313 - 2⁴ = 688969297 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (53), and also a Moran number because the ratio is a prime number: 12999421 = 688969313 / (6 + 8 + 8 + 9 + 6 + 9 + 3 + 1 + 3).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (688909313) 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, 6499658 + ... + 6499763.

It is an arithmetic number, because the mean of its divisors is an integer number (175492197).

Almost surely, 2^688969313 is an apocalyptic number.

It is an amenable number.

688969313 is a deficient number, since it is larger than the sum of its proper divisors (12999475).

688969313 is a wasteful number, since it uses less digits than its factorization.

688969313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12999474.

The product of its digits is 1679616, while the sum is 53.

The square root of 688969313 is about 26248.2249495085. The cubic root of 688969313 is about 883.2153863483.

The spelling of 688969313 in words is "six hundred eighty-eight million, nine hundred sixty-nine thousand, three hundred thirteen".