636974783449 has 9 divisors (see below), whose sum is σ = 650854121151. Its totient is φ = 623385415560.

The previous prime is 636974783441. The next prime is 636974783483. The reversal of 636974783449 is 944387479636.

The square root of 636974783449 is 798107.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 624879183049 + 12095600400 = 790493^2 + 109980^2 .

It is not a de Polignac number, because 636974783449 - 2³ = 636974783441 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (636974783441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 37502539 + ... + 37519519.

Almost surely, 2^636974783449 is an apocalyptic number.

636974783449 is the 798107-th square number.

636974783449 is the 399054-th centered octagonal number.

It is an amenable number.

636974783449 is a deficient number, since it is larger than the sum of its proper divisors (13879337702).

636974783449 is an frugal number, since it uses more digits than its factorization.

636974783449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34056 (or 17028 counting only the distinct ones).

The product of its digits is 658409472, while the sum is 70.

The spelling of 636974783449 in words is "six hundred thirty-six billion, nine hundred seventy-four million, seven hundred eighty-three thousand, four hundred forty-nine".