687863009 has 2 divisors, whose sum is σ = 687863010. Its totient is φ = 687863008.

The previous prime is 687863003. The next prime is 687863117. The reversal of 687863009 is 900368786.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 674700625 + 13162384 = 25975^2 + 3628^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-687863009 is a prime.

It is not a weakly prime, because it can be changed into another prime (687863003) 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, 343931504 + 343931505.

It is an arithmetic number, because the mean of its divisors is an integer number (343931505).

Almost surely, 2^687863009 is an apocalyptic number.

It is an amenable number.

687863009 is a deficient number, since it is larger than the sum of its proper divisors (1).

687863009 is an equidigital number, since it uses as much as digits as its factorization.

687863009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 435456, while the sum is 47.

The square root of 687863009 is about 26227.1426007486. The cubic root of 687863009 is about 882.7423956772.

The spelling of 687863009 in words is "six hundred eighty-seven million, eight hundred sixty-three thousand, nine".