688850609 has 2 divisors, whose sum is σ = 688850610. Its totient is φ = 688850608.

The previous prime is 688850441. The next prime is 688850611. The reversal of 688850609 is 906058886.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 453903025 + 234947584 = 21305^2 + 15328^2 .

It is a cyclic number.

It is not a de Polignac number, because 688850609 - 2¹² = 688846513 is a prime.

Together with 688850611, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (688850689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344425304 + 344425305.

It is an arithmetic number, because the mean of its divisors is an integer number (344425305).

Almost surely, 2^688850609 is an apocalyptic number.

It is an amenable number.

688850609 is a deficient number, since it is larger than the sum of its proper divisors (1).

688850609 is an equidigital number, since it uses as much as digits as its factorization.

688850609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 829440, while the sum is 50.

The square root of 688850609 is about 26245.9636706294. The cubic root of 688850609 is about 883.1646597441.

The spelling of 688850609 in words is "six hundred eighty-eight million, eight hundred fifty thousand, six hundred nine".