636728985 has 16 divisors (see below), whose sum is σ = 1131962880. Its totient is φ = 339588720.

The previous prime is 636728977. The next prime is 636729011. The reversal of 636728985 is 589827636.

It is a happy number.

It is not a de Polignac number, because 636728985 - 2³ = 636728977 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2358121 + ... + 2358390.

It is an arithmetic number, because the mean of its divisors is an integer number (70747680).

Almost surely, 2^636728985 is an apocalyptic number.

It is an amenable number.

636728985 is a deficient number, since it is larger than the sum of its proper divisors (495233895).

636728985 is a wasteful number, since it uses less digits than its factorization.

636728985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4716525 (or 4716519 counting only the distinct ones).

The product of its digits is 4354560, while the sum is 54.

The square root of 636728985 is about 25233.4893544274. The cubic root of 636728985 is about 860.3032034373.

The spelling of 636728985 in words is "six hundred thirty-six million, seven hundred twenty-eight thousand, nine hundred eighty-five".