636041309 has 2 divisors, whose sum is σ = 636041310. Its totient is φ = 636041308.

The previous prime is 636041297. The next prime is 636041347. The reversal of 636041309 is 903140636.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 332515225 + 303526084 = 18235^2 + 17422^2 .

It is a cyclic number.

It is not a de Polignac number, because 636041309 - 2⁴ = 636041293 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (636041389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 318020654 + 318020655.

It is an arithmetic number, because the mean of its divisors is an integer number (318020655).

Almost surely, 2^636041309 is an apocalyptic number.

It is an amenable number.

636041309 is a deficient number, since it is larger than the sum of its proper divisors (1).

636041309 is an equidigital number, since it uses as much as digits as its factorization.

636041309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11664, while the sum is 32.

The square root of 636041309 is about 25219.8594167374. The cubic root of 636041309 is about 859.9933788025.

The spelling of 636041309 in words is "six hundred thirty-six million, forty-one thousand, three hundred nine".