646261313 has 2 divisors, whose sum is σ = 646261314. Its totient is φ = 646261312.

The previous prime is 646261289. The next prime is 646261321. The reversal of 646261313 is 313162646.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 636199729 + 10061584 = 25223^2 + 3172^2 .

It is a cyclic number.

It is not a de Polignac number, because 646261313 - 2⁶ = 646261249 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 646261313.

It is not a weakly prime, because it can be changed into another prime (646261373) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323130656 + 323130657.

It is an arithmetic number, because the mean of its divisors is an integer number (323130657).

Almost surely, 2^646261313 is an apocalyptic number.

It is an amenable number.

646261313 is a deficient number, since it is larger than the sum of its proper divisors (1).

646261313 is an equidigital number, since it uses as much as digits as its factorization.

646261313 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15552, while the sum is 32.

The square root of 646261313 is about 25421.6701457634. The cubic root of 646261313 is about 864.5750919655.

The spelling of 646261313 in words is "six hundred forty-six million, two hundred sixty-one thousand, three hundred thirteen".