688301309 has 2 divisors, whose sum is σ = 688301310. Its totient is φ = 688301308.

The previous prime is 688301303. The next prime is 688301431. The reversal of 688301309 is 903103886.

688301309 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 684607225 + 3694084 = 26165^2 + 1922^2 .

It is a cyclic number.

It is not a de Polignac number, because 688301309 - 2¹⁶ = 688235773 is a prime.

It is a super-2 number, since 2×688301309² = 947517383942226962, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (688301303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344150654 + 344150655.

It is an arithmetic number, because the mean of its divisors is an integer number (344150655).

Almost surely, 2^688301309 is an apocalyptic number.

It is an amenable number.

688301309 is a deficient number, since it is larger than the sum of its proper divisors (1).

688301309 is an equidigital number, since it uses as much as digits as its factorization.

688301309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31104, while the sum is 38.

The square root of 688301309 is about 26235.4971174552. The cubic root of 688301309 is about 882.9298476545.

The spelling of 688301309 in words is "six hundred eighty-eight million, three hundred one thousand, three hundred nine".