646213517 has 2 divisors, whose sum is σ = 646213518. Its totient is φ = 646213516.

The previous prime is 646213433. The next prime is 646213523. The reversal of 646213517 is 715312646.

646213517 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 641659561 + 4553956 = 25331^2 + 2134^2 .

It is a cyclic number.

It is not a de Polignac number, because 646213517 - 2¹⁰ = 646212493 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (646213567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323106758 + 323106759.

It is an arithmetic number, because the mean of its divisors is an integer number (323106759).

Almost surely, 2^646213517 is an apocalyptic number.

It is an amenable number.

646213517 is a deficient number, since it is larger than the sum of its proper divisors (1).

646213517 is an equidigital number, since it uses as much as digits as its factorization.

646213517 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30240, while the sum is 35.

The square root of 646213517 is about 25420.7300642605. The cubic root of 646213517 is about 864.5537774451.

The spelling of 646213517 in words is "six hundred forty-six million, two hundred thirteen thousand, five hundred seventeen".