646831013 has 2 divisors, whose sum is σ = 646831014. Its totient is φ = 646831012.

The previous prime is 646830991. The next prime is 646831033. The reversal of 646831013 is 310138646.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 542750209 + 104080804 = 23297^2 + 10202^2 .

It is a cyclic number.

It is not a de Polignac number, because 646831013 - 2⁶ = 646830949 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 (646831033) 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, 323415506 + 323415507.

It is an arithmetic number, because the mean of its divisors is an integer number (323415507).

Almost surely, 2^646831013 is an apocalyptic number.

It is an amenable number.

646831013 is a deficient number, since it is larger than the sum of its proper divisors (1).

646831013 is an equidigital number, since it uses as much as digits as its factorization.

646831013 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 646831013 is about 25432.8726847755. The cubic root of 646831013 is about 864.8290675419.

Adding to 646831013 its reverse (310138646), we get a palindrome (956969659).

The spelling of 646831013 in words is "six hundred forty-six million, eight hundred thirty-one thousand, thirteen".