643504448 has 112 divisors (see below), whose sum is σ = 1379549184. Its totient is φ = 297285120.

The previous prime is 643504447. The next prime is 643504501. The reversal of 643504448 is 844405346.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643504447) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6247565 + ... + 6247667.

Almost surely, 2^643504448 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 643504448, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (689774592).

643504448 is an abundant number, since it is smaller than the sum of its proper divisors (736044736).

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

643504448 is a wasteful number, since it uses less digits than its factorization.

643504448 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 260 (or 250 counting only the distinct ones).

The product of its (nonzero) digits is 184320, while the sum is 38.

The square root of 643504448 is about 25367.3894596981. The cubic root of 643504448 is about 863.3439521394.

The spelling of 643504448 in words is "six hundred forty-three million, five hundred four thousand, four hundred forty-eight".