636344772 has 144 divisors (see below), whose sum is σ = 1818980352. Its totient is φ = 172307520.

The previous prime is 636344747. The next prime is 636344773. The reversal of 636344772 is 277443636.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (636344773) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2853453 + ... + 2853675.

It is an arithmetic number, because the mean of its divisors is an integer number (12631808).

Almost surely, 2^636344772 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 636344772, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (909490176).

636344772 is an abundant number, since it is smaller than the sum of its proper divisors (1182635580).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

636344772 is a wasteful number, since it uses less digits than its factorization.

636344772 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 478 (or 469 counting only the distinct ones).

The product of its digits is 508032, while the sum is 42.

The square root of 636344772 is about 25225.8750492426. The cubic root of 636344772 is about 860.1301281367.

The spelling of 636344772 in words is "six hundred thirty-six million, three hundred forty-four thousand, seven hundred seventy-two".