636985666 has 16 divisors (see below), whose sum is σ = 964548288. Its totient is φ = 315478800.

The previous prime is 636985649. The next prime is 636985669. The reversal of 636985666 is 666589636.

636985666 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (636985669) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 163396 + ... + 167248.

It is an arithmetic number, because the mean of its divisors is an integer number (60284268).

Almost surely, 2^636985666 is an apocalyptic number.

636985666 is a deficient number, since it is larger than the sum of its proper divisors (327562622).

636985666 is a wasteful number, since it uses less digits than its factorization.

636985666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4617.

The product of its digits is 8398080, while the sum is 55.

The square root of 636985666 is about 25238.5749597714. The cubic root of 636985666 is about 860.4187909820.

The spelling of 636985666 in words is "six hundred thirty-six million, nine hundred eighty-five thousand, six hundred sixty-six".