634667609 has 2 divisors, whose sum is σ = 634667610. Its totient is φ = 634667608.

The previous prime is 634667603. The next prime is 634667669. The reversal of 634667609 is 906766436.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 634032400 + 635209 = 25180^2 + 797^2 .

It is a cyclic number.

It is not a de Polignac number, because 634667609 - 2⁸ = 634667353 is a prime.

It is not a weakly prime, because it can be changed into another prime (634667603) 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, 317333804 + 317333805.

It is an arithmetic number, because the mean of its divisors is an integer number (317333805).

Almost surely, 2^634667609 is an apocalyptic number.

It is an amenable number.

634667609 is a deficient number, since it is larger than the sum of its proper divisors (1).

634667609 is an equidigital number, since it uses as much as digits as its factorization.

634667609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 979776, while the sum is 47.

The square root of 634667609 is about 25192.6102061696. The cubic root of 634667609 is about 859.3738045674.

The spelling of 634667609 in words is "six hundred thirty-four million, six hundred sixty-seven thousand, six hundred nine".