688643369 has 2 divisors, whose sum is σ = 688643370. Its totient is φ = 688643368.

The previous prime is 688643303. The next prime is 688643377. The reversal of 688643369 is 963346886.

688643369 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 585010969 + 103632400 = 24187^2 + 10180^2 .

It is a cyclic number.

It is not a de Polignac number, because 688643369 - 2¹⁶ = 688577833 is a prime.

It is a super-2 number, since 2×688643369² = 948459379335340322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 688643369.

It is not a weakly prime, because it can be changed into another prime (688643399) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344321684 + 344321685.

It is an arithmetic number, because the mean of its divisors is an integer number (344321685).

Almost surely, 2^688643369 is an apocalyptic number.

It is an amenable number.

688643369 is a deficient number, since it is larger than the sum of its proper divisors (1).

688643369 is an equidigital number, since it uses as much as digits as its factorization.

688643369 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4478976, while the sum is 53.

The square root of 688643369 is about 26242.0153380033. The cubic root of 688643369 is about 883.0760844665.

The spelling of 688643369 in words is "six hundred eighty-eight million, six hundred forty-three thousand, three hundred sixty-nine".