646354213 has 2 divisors, whose sum is σ = 646354214. Its totient is φ = 646354212.

The previous prime is 646354207. The next prime is 646354253. The reversal of 646354213 is 312453646.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 567535329 + 78818884 = 23823^2 + 8878^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-646354213 is a prime.

It is equal to p_33613648 and since 646354213 and 33613648 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (646354253) 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, 323177106 + 323177107.

It is an arithmetic number, because the mean of its divisors is an integer number (323177107).

Almost surely, 2^646354213 is an apocalyptic number.

It is an amenable number.

646354213 is a deficient number, since it is larger than the sum of its proper divisors (1).

646354213 is an equidigital number, since it uses as much as digits as its factorization.

646354213 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 51840, while the sum is 34.

The square root of 646354213 is about 25423.4972613919. The cubic root of 646354213 is about 864.6165175087.

The spelling of 646354213 in words is "six hundred forty-six million, three hundred fifty-four thousand, two hundred thirteen".