636443980 has 12 divisors (see below), whose sum is σ = 1336532400. Its totient is φ = 254577584.

The previous prime is 636443939. The next prime is 636443999. The reversal of 636443980 is 89344636.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15911080 + ... + 15911119.

It is an arithmetic number, because the mean of its divisors is an integer number (111377700).

Almost surely, 2^636443980 is an apocalyptic number.

It is an amenable number.

636443980 is an abundant number, since it is smaller than the sum of its proper divisors (700088420).

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

636443980 is a wasteful number, since it uses less digits than its factorization.

636443980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31822208 (or 31822206 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 43.

The square root of 636443980 is about 25227.8413662366. The cubic root of 636443980 is about 860.1748247433.

The spelling of 636443980 in words is "six hundred thirty-six million, four hundred forty-three thousand, nine hundred eighty".