636648847 has 2 divisors, whose sum is σ = 636648848. Its totient is φ = 636648846.

The previous prime is 636648833. The next prime is 636648863. The reversal of 636648847 is 748846636.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-636648847 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 636648794 and 636648803.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (636648877) 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, 318324423 + 318324424.

It is an arithmetic number, because the mean of its divisors is an integer number (318324424).

Almost surely, 2^636648847 is an apocalyptic number.

636648847 is a deficient number, since it is larger than the sum of its proper divisors (1).

636648847 is an equidigital number, since it uses as much as digits as its factorization.

636648847 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4644864, while the sum is 52.

The square root of 636648847 is about 25231.9013750450. The cubic root of 636648847 is about 860.2671096558.

The spelling of 636648847 in words is "six hundred thirty-six million, six hundred forty-eight thousand, eight hundred forty-seven".