634688309 has 2 divisors, whose sum is σ = 634688310. Its totient is φ = 634688308.

The previous prime is 634688279. The next prime is 634688359. The reversal of 634688309 is 903886436.

634688309 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., 596434084 + 38254225 = 24422^2 + 6185^2 .

It is a cyclic number.

It is not a de Polignac number, because 634688309 - 2¹² = 634684213 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (634688359) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 317344154 + 317344155.

It is an arithmetic number, because the mean of its divisors is an integer number (317344155).

Almost surely, 2^634688309 is an apocalyptic number.

It is an amenable number.

634688309 is a deficient number, since it is larger than the sum of its proper divisors (1).

634688309 is an equidigital number, since it uses as much as digits as its factorization.

634688309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 746496, while the sum is 47.

The square root of 634688309 is about 25193.0210375810. The cubic root of 634688309 is about 859.3831474339.

The spelling of 634688309 in words is "six hundred thirty-four million, six hundred eighty-eight thousand, three hundred nine".