636644087 has 2 divisors, whose sum is σ = 636644088. Its totient is φ = 636644086.

The previous prime is 636644081. The next prime is 636644131. The reversal of 636644087 is 780446636.

It is a happy number.

It is an a-pointer prime, because the next prime (636644131) can be obtained adding 636644087 to its sum of digits (44).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 636644087 - 2⁸ = 636643831 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (636644081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 318322043 + 318322044.

It is an arithmetic number, because the mean of its divisors is an integer number (318322044).

Almost surely, 2^636644087 is an apocalyptic number.

636644087 is a deficient number, since it is larger than the sum of its proper divisors (1).

636644087 is an equidigital number, since it uses as much as digits as its factorization.

636644087 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 580608, while the sum is 44.

The square root of 636644087 is about 25231.8070498330. The cubic root of 636644087 is about 860.2649656787.

The spelling of 636644087 in words is "six hundred thirty-six million, six hundred forty-four thousand, eighty-seven".