687634039 has 2 divisors, whose sum is σ = 687634040. Its totient is φ = 687634038.

The previous prime is 687633983. The next prime is 687634043. The reversal of 687634039 is 930436786.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-687634039 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 687634039.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (687634069) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343817019 + 343817020.

It is an arithmetic number, because the mean of its divisors is an integer number (343817020).

Almost surely, 2^687634039 is an apocalyptic number.

687634039 is a deficient number, since it is larger than the sum of its proper divisors (1).

687634039 is an equidigital number, since it uses as much as digits as its factorization.

687634039 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 653184, while the sum is 46.

The square root of 687634039 is about 26222.7771031216. Note that the first 3 decimals coincide. The cubic root of 687634039 is about 882.6444382086.

The spelling of 687634039 in words is "six hundred eighty-seven million, six hundred thirty-four thousand, thirty-nine".