636109 has 2 divisors, whose sum is σ = 636110. Its totient is φ = 636108.

The previous prime is 636107. The next prime is 636133. The reversal of 636109 is 901636.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 635209 + 900 = 797^2 + 30^2 .

It is a cyclic number.

It is not a de Polignac number, because 636109 - 2¹ = 636107 is a prime.

Together with 636107, it forms a pair of twin primes.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (636107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 318054 + 318055.

It is an arithmetic number, because the mean of its divisors is an integer number (318055).

2⁶³⁶¹⁰⁹ is an apocalyptic number.

It is an amenable number.

636109 is a deficient number, since it is larger than the sum of its proper divisors (1).

636109 is an equidigital number, since it uses as much as digits as its factorization.

636109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 972, while the sum is 25.

The square root of 636109 is about 797.5644174611. The cubic root of 636109 is about 86.0023886122.

The spelling of 636109 in words is "six hundred thirty-six thousand, one hundred nine".