646721303 has 2 divisors, whose sum is σ = 646721304. Its totient is φ = 646721302.

The previous prime is 646721279. The next prime is 646721311. The reversal of 646721303 is 303127646.

646721303 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 is a cyclic number.

It is not a de Polignac number, because 646721303 - 2¹⁶ = 646655767 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 646721303.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (646721323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323360651 + 323360652.

It is an arithmetic number, because the mean of its divisors is an integer number (323360652).

Almost surely, 2^646721303 is an apocalyptic number.

646721303 is a deficient number, since it is larger than the sum of its proper divisors (1).

646721303 is an equidigital number, since it uses as much as digits as its factorization.

646721303 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18144, while the sum is 32.

The square root of 646721303 is about 25430.7157390428. The cubic root of 646721303 is about 864.7801697824.

Adding to 646721303 its reverse (303127646), we get a palindrome (949848949).

The spelling of 646721303 in words is "six hundred forty-six million, seven hundred twenty-one thousand, three hundred three".