628385809 has 2 divisors, whose sum is σ = 628385810. Its totient is φ = 628385808.

The previous prime is 628385801. The next prime is 628385843. The reversal of 628385809 is 908583826.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 610238209 + 18147600 = 24703^2 + 4260^2 .

It is a cyclic number.

It is not a de Polignac number, because 628385809 - 2³ = 628385801 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (628385801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 314192904 + 314192905.

It is an arithmetic number, because the mean of its divisors is an integer number (314192905).

Almost surely, 2^628385809 is an apocalyptic number.

It is an amenable number.

628385809 is a deficient number, since it is larger than the sum of its proper divisors (1).

628385809 is an equidigital number, since it uses as much as digits as its factorization.

628385809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 829440, while the sum is 49.

The square root of 628385809 is about 25067.6247179504. The cubic root of 628385809 is about 856.5291009522.

The spelling of 628385809 in words is "six hundred twenty-eight million, three hundred eighty-five thousand, eight hundred nine".