636663541 has 2 divisors, whose sum is σ = 636663542. Its totient is φ = 636663540.

The previous prime is 636663491. The next prime is 636663553. The reversal of 636663541 is 145366636.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 517744516 + 118919025 = 22754^2 + 10905^2 .

It is a cyclic number.

It is not a de Polignac number, because 636663541 - 2⁹ = 636663029 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 636663494 and 636663503.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (636663241) 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, 318331770 + 318331771.

It is an arithmetic number, because the mean of its divisors is an integer number (318331771).

Almost surely, 2^636663541 is an apocalyptic number.

It is an amenable number.

636663541 is a deficient number, since it is larger than the sum of its proper divisors (1).

636663541 is an equidigital number, since it uses as much as digits as its factorization.

636663541 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 233280, while the sum is 40.

The square root of 636663541 is about 25232.1925523725. The cubic root of 636663541 is about 860.2737279916.

The spelling of 636663541 in words is "six hundred thirty-six million, six hundred sixty-three thousand, five hundred forty-one".