646623317 has 2 divisors, whose sum is σ = 646623318. Its totient is φ = 646623316.

The previous prime is 646623287. The next prime is 646623323. The reversal of 646623317 is 713326646.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 477597316 + 169026001 = 21854^2 + 13001^2 .

It is a cyclic number.

It is not a de Polignac number, because 646623317 - 2⁶ = 646623253 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (646623377) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323311658 + 323311659.

It is an arithmetic number, because the mean of its divisors is an integer number (323311659).

Almost surely, 2^646623317 is an apocalyptic number.

It is an amenable number.

646623317 is a deficient number, since it is larger than the sum of its proper divisors (1).

646623317 is an equidigital number, since it uses as much as digits as its factorization.

646623317 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108864, while the sum is 38.

The square root of 646623317 is about 25428.7891375111. The cubic root of 646623317 is about 864.7364927358.

The spelling of 646623317 in words is "six hundred forty-six million, six hundred twenty-three thousand, three hundred seventeen".