643805504 has 56 divisors (see below), whose sum is σ = 1361678760. Its totient is φ = 300957696.

The previous prime is 643805467. The next prime is 643805507. The reversal of 643805504 is 405508346.

It can be written as a sum of positive squares in 4 ways, for example, as 213160000 + 430645504 = 14600^2 + 20752^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643805507) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 168932 + ... + 172700.

Almost surely, 2^643805504 is an apocalyptic number.

643805504 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643805504, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (680839380).

643805504 is an abundant number, since it is smaller than the sum of its proper divisors (717873256).

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

643805504 is a wasteful number, since it uses less digits than its factorization.

643805504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3955 (or 3945 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 35.

The square root of 643805504 is about 25373.3226834800. The cubic root of 643805504 is about 863.4785662592.

The spelling of 643805504 in words is "six hundred forty-three million, eight hundred five thousand, five hundred four".