646444323444649 has 2 divisors, whose sum is σ = 646444323444650. Its totient is φ = 646444323444648.

The previous prime is 646444323444629. The next prime is 646444323444707. The reversal of 646444323444649 is 946444323444646.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 387348846192400 + 259095477252249 = 19681180^2 + 16096443^2 .

It is a cyclic number.

It is not a de Polignac number, because 646444323444649 - 2⁹ = 646444323444137 is a prime.

It is not a weakly prime, because it can be changed into another prime (646444323444629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323222161722324 + 323222161722325.

It is an arithmetic number, because the mean of its divisors is an integer number (323222161722325).

Almost surely, 2^{646444323444649} is an apocalyptic number.

It is an amenable number.

646444323444649 is a deficient number, since it is larger than the sum of its proper divisors (1).

646444323444649 is an equidigital number, since it uses as much as digits as its factorization.

646444323444649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2293235712, while the sum is 67.

The spelling of 646444323444649 in words is "six hundred forty-six trillion, four hundred forty-four billion, three hundred twenty-three million, four hundred forty-four thousand, six hundred forty-nine".