628197509 has 2 divisors, whose sum is σ = 628197510. Its totient is φ = 628197508.

The previous prime is 628197469. The next prime is 628197523. The reversal of 628197509 is 905791826.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 617373409 + 10824100 = 24847^2 + 3290^2 .

It is a cyclic number.

It is not a de Polignac number, because 628197509 - 2¹² = 628193413 is a prime.

It is a super-2 number, since 2×628197509² = 789264220627610162, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (628197569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 314098754 + 314098755.

It is an arithmetic number, because the mean of its divisors is an integer number (314098755).

Almost surely, 2^628197509 is an apocalyptic number.

It is an amenable number.

628197509 is a deficient number, since it is larger than the sum of its proper divisors (1).

628197509 is an equidigital number, since it uses as much as digits as its factorization.

628197509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 272160, while the sum is 47.

The square root of 628197509 is about 25063.8685960488. The cubic root of 628197509 is about 856.4435375186.

The spelling of 628197509 in words is "six hundred twenty-eight million, one hundred ninety-seven thousand, five hundred nine".