687643907 has 2 divisors, whose sum is σ = 687643908. Its totient is φ = 687643906.

The previous prime is 687643843. The next prime is 687643933. The reversal of 687643907 is 709346786.

687643907 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 is a cyclic number.

It is not a de Polignac number, because 687643907 - 2⁶ = 687643843 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (687643937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343821953 + 343821954.

It is an arithmetic number, because the mean of its divisors is an integer number (343821954).

Almost surely, 2^687643907 is an apocalyptic number.

687643907 is a deficient number, since it is larger than the sum of its proper divisors (1).

687643907 is an equidigital number, since it uses as much as digits as its factorization.

687643907 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1524096, while the sum is 50.

The square root of 687643907 is about 26222.9652594820. The cubic root of 687643907 is about 882.6486603642.

The spelling of 687643907 in words is "six hundred eighty-seven million, six hundred forty-three thousand, nine hundred seven".