643422 has 32 divisors (see below), whose sum is σ = 1417248. Its totient is φ = 193536.

The previous prime is 643421. The next prime is 643429. The reversal of 643422 is 224346.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5638 + ... + 5750.

It is an arithmetic number, because the mean of its divisors is an integer number (44289).

2⁶⁴³⁴²² is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643422, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (708624).

643422 is an abundant number, since it is smaller than the sum of its proper divisors (773826).

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

643422 is a wasteful number, since it uses less digits than its factorization.

643422 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204.

The product of its digits is 1152, while the sum is 21.

The square root of 643422 is about 802.1358987104. The cubic root of 643422 is about 86.3307079034.

Adding to 643422 its reverse (224346), we get a palindrome (867768).

It can be divided in two parts, 64 and 3422, that added together give a triangular number (3486 = T₈₃).

The spelling of 643422 in words is "six hundred forty-three thousand, four hundred twenty-two".