646396913 has 2 divisors, whose sum is σ = 646396914. Its totient is φ = 646396912.

The previous prime is 646396909. The next prime is 646396937. The reversal of 646396913 is 319693646.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 556393744 + 90003169 = 23588^2 + 9487^2 .

It is a cyclic number.

It is not a de Polignac number, because 646396913 - 2² = 646396909 is a prime.

It is not a weakly prime, because it can be changed into another prime (646396963) 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, 323198456 + 323198457.

It is an arithmetic number, because the mean of its divisors is an integer number (323198457).

Almost surely, 2^646396913 is an apocalyptic number.

It is an amenable number.

646396913 is a deficient number, since it is larger than the sum of its proper divisors (1).

646396913 is an equidigital number, since it uses as much as digits as its factorization.

646396913 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 629856, while the sum is 47.

The square root of 646396913 is about 25424.3370218380. The cubic root of 646396913 is about 864.6355567659.

The spelling of 646396913 in words is "six hundred forty-six million, three hundred ninety-six thousand, nine hundred thirteen".