636644741 has 2 divisors, whose sum is σ = 636644742. Its totient is φ = 636644740.

The previous prime is 636644719. The next prime is 636644779. The reversal of 636644741 is 147446636.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 525784900 + 110859841 = 22930^2 + 10529^2 .

It is a cyclic number.

It is not a de Polignac number, because 636644741 - 2⁶ = 636644677 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (636644641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 318322370 + 318322371.

It is an arithmetic number, because the mean of its divisors is an integer number (318322371).

Almost surely, 2^636644741 is an apocalyptic number.

It is an amenable number.

636644741 is a deficient number, since it is larger than the sum of its proper divisors (1).

636644741 is an equidigital number, since it uses as much as digits as its factorization.

636644741 is an evil number, because the sum of its binary digits is even.

The product of its digits is 290304, while the sum is 41.

The square root of 636644741 is about 25231.8200096624. The cubic root of 636644741 is about 860.2652602509.

The spelling of 636644741 in words is "six hundred thirty-six million, six hundred forty-four thousand, seven hundred forty-one".