636447947 has 6 divisors (see below), whose sum is σ = 640016604. Its totient is φ = 632899080.

The previous prime is 636447919. The next prime is 636447967. The reversal of 636447947 is 749744636.

It is not a de Polignac number, because 636447947 - 2¹² = 636443851 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 636447895 and 636447904.

It is not an unprimeable number, because it can be changed into a prime (636447967) 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 5 ways as a sum of consecutive naturals, for example, 23048 + ... + 42474.

It is an arithmetic number, because the mean of its divisors is an integer number (106669434).

Almost surely, 2^636447947 is an apocalyptic number.

636447947 is a deficient number, since it is larger than the sum of its proper divisors (3568657).

636447947 is an equidigital number, since it uses as much as digits as its factorization.

636447947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19789 (or 19608 counting only the distinct ones).

The product of its digits is 3048192, while the sum is 50.

The square root of 636447947 is about 25227.9199895671. The cubic root of 636447947 is about 860.1766119162.

The spelling of 636447947 in words is "six hundred thirty-six million, four hundred forty-seven thousand, nine hundred forty-seven".