688249643 has 2 divisors, whose sum is σ = 688249644. Its totient is φ = 688249642.

The previous prime is 688249637. The next prime is 688249651. The reversal of 688249643 is 346942886.

It is a happy number.

688249643 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 is a cyclic number.

It is not a de Polignac number, because 688249643 - 2⁶ = 688249579 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 688249591 and 688249600.

It is not a weakly prime, because it can be changed into another prime (688249843) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344124821 + 344124822.

It is an arithmetic number, because the mean of its divisors is an integer number (344124822).

Almost surely, 2^688249643 is an apocalyptic number.

688249643 is a deficient number, since it is larger than the sum of its proper divisors (1).

688249643 is an equidigital number, since it uses as much as digits as its factorization.

688249643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1990656, while the sum is 50.

The square root of 688249643 is about 26234.5124406763. The cubic root of 688249643 is about 882.9077552974.

The spelling of 688249643 in words is "six hundred eighty-eight million, two hundred forty-nine thousand, six hundred forty-three".