628813309 has 2 divisors, whose sum is σ = 628813310. Its totient is φ = 628813308.

The previous prime is 628813301. The next prime is 628813319. The reversal of 628813309 is 903318826.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 458902084 + 169911225 = 21422^2 + 13035^2 .

It is a cyclic number.

It is not a de Polignac number, because 628813309 - 2³ = 628813301 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (628813301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 314406654 + 314406655.

It is an arithmetic number, because the mean of its divisors is an integer number (314406655).

Almost surely, 2^628813309 is an apocalyptic number.

It is an amenable number.

628813309 is a deficient number, since it is larger than the sum of its proper divisors (1).

628813309 is an equidigital number, since it uses as much as digits as its factorization.

628813309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 62208, while the sum is 40.

The square root of 628813309 is about 25076.1502029319. The cubic root of 628813309 is about 856.7232933208.

The spelling of 628813309 in words is "six hundred twenty-eight million, eight hundred thirteen thousand, three hundred nine".