634660909 has 2 divisors, whose sum is σ = 634660910. Its totient is φ = 634660908.

The previous prime is 634660903. The next prime is 634660921. The reversal of 634660909 is 909066436.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 586705284 + 47955625 = 24222^2 + 6925^2 .

It is a cyclic number.

It is not a de Polignac number, because 634660909 - 2¹⁹ = 634136621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (634660903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 317330454 + 317330455.

It is an arithmetic number, because the mean of its divisors is an integer number (317330455).

Almost surely, 2^634660909 is an apocalyptic number.

It is an amenable number.

634660909 is a deficient number, since it is larger than the sum of its proper divisors (1).

634660909 is an equidigital number, since it uses as much as digits as its factorization.

634660909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 209952, while the sum is 43.

The square root of 634660909 is about 25192.4772303162. The cubic root of 634660909 is about 859.3707805042.

The spelling of 634660909 in words is "six hundred thirty-four million, six hundred sixty thousand, nine hundred nine".