643423 has 8 divisors (see below), whose sum is σ = 726480. Its totient is φ = 564480.

The previous prime is 643421. The next prime is 643429. The reversal of 643423 is 324346.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 643423 - 2¹ = 643421 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 643394 and 643403.

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 polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 690 + ... + 1327.

It is an arithmetic number, because the mean of its divisors is an integer number (90810).

2⁶⁴³⁴²³ is an apocalyptic number.

643423 is a deficient number, since it is larger than the sum of its proper divisors (83057).

643423 is a wasteful number, since it uses less digits than its factorization.

643423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2057.

The product of its digits is 1728, while the sum is 22.

The square root of 643423 is about 802.1365220460. The cubic root of 643423 is about 86.3307526281.

Adding to 643423 its reverse (324346), we get a palindrome (967769).

The spelling of 643423 in words is "six hundred forty-three thousand, four hundred twenty-three".