636945663 has 16 divisors (see below), whose sum is σ = 854332416. Its totient is φ = 422102880.

The previous prime is 636945649. The next prime is 636945671. The reversal of 636945663 is 366549636.

It is not a de Polignac number, because 636945663 - 2⁶ = 636945599 is a prime.

It is a super-2 number, since 2×636945663² = 811399555229019138, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (636945643) 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 in 15 ways as a sum of consecutive naturals, for example, 647470 + ... + 648452.

It is an arithmetic number, because the mean of its divisors is an integer number (53395776).

Almost surely, 2^636945663 is an apocalyptic number.

636945663 is a deficient number, since it is larger than the sum of its proper divisors (217386753).

636945663 is a wasteful number, since it uses less digits than its factorization.

636945663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2054.

The product of its digits is 2099520, while the sum is 48.

The square root of 636945663 is about 25237.7824501282. The cubic root of 636945663 is about 860.4007790365.

The spelling of 636945663 in words is "six hundred thirty-six million, nine hundred forty-five thousand, six hundred sixty-three".