643530 has 32 divisors (see below), whose sum is σ = 1627200. Its totient is φ = 162432.

The previous prime is 643523. The next prime is 643547. The reversal of 643530 is 35346.

643530 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is a nialpdrome in base 15.

It is a junction number, because it is equal to n+sod(n) for n = 643497 and 643506.

It is an unprimeable number.

643530 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6 + ... + 1134.

It is an arithmetic number, because the mean of its divisors is an integer number (50850).

2⁶⁴³⁵³⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643530, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (813600).

643530 is an abundant number, since it is smaller than the sum of its proper divisors (983670).

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

643530 is a wasteful number, since it uses less digits than its factorization.

643530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1158.

The product of its (nonzero) digits is 1080, while the sum is 21.

The square root of 643530 is about 802.2032161491. The cubic root of 643530 is about 86.3355379086.

Adding to 643530 its reverse (35346), we get a palindrome (678876).

The spelling of 643530 in words is "six hundred forty-three thousand, five hundred thirty".