643630 has 16 divisors (see below), whose sum is σ = 1247904. Its totient is φ = 237600.

The previous prime is 643619. The next prime is 643633. The reversal of 643630 is 36346.

643630 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643633) 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, 2346 + ... + 2605.

It is an arithmetic number, because the mean of its divisors is an integer number (77994).

2⁶⁴³⁶³⁰ is an apocalyptic number.

643630 is a deficient number, since it is larger than the sum of its proper divisors (604274).

643630 is a wasteful number, since it uses less digits than its factorization.

643630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4971.

The product of its (nonzero) digits is 1296, while the sum is 22.

The square root of 643630 is about 802.2655420744. The cubic root of 643630 is about 86.3400096538.

Adding to 643630 its reverse (36346), we get a palindrome (679976).

The spelling of 643630 in words is "six hundred forty-three thousand, six hundred thirty".