646816507 has 2 divisors, whose sum is σ = 646816508. Its totient is φ = 646816506.

The previous prime is 646816501. The next prime is 646816523. The reversal of 646816507 is 705618646.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 646816507 - 2¹¹ = 646814459 is a prime.

It is not a weakly prime, because it can be changed into another prime (646816501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323408253 + 323408254.

It is an arithmetic number, because the mean of its divisors is an integer number (323408254).

Almost surely, 2^646816507 is an apocalyptic number.

646816507 is a deficient number, since it is larger than the sum of its proper divisors (1).

646816507 is an equidigital number, since it uses as much as digits as its factorization.

646816507 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 241920, while the sum is 43.

The square root of 646816507 is about 25432.5875010782. The cubic root of 646816507 is about 864.8226025332.

The spelling of 646816507 in words is "six hundred forty-six million, eight hundred sixteen thousand, five hundred seven".