643173 has 4 divisors (see below), whose sum is σ = 857568. Its totient is φ = 428780.

The previous prime is 643129. The next prime is 643183. The reversal of 643173 is 371346.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 643173 - 2¹⁰ = 642149 is a prime.

It is a D-number.

643173 is a lucky number.

It is a nialpdrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643183) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 107193 + ... + 107198.

It is an arithmetic number, because the mean of its divisors is an integer number (214392).

2⁶⁴³¹⁷³ is an apocalyptic number.

It is an amenable number.

643173 is a deficient number, since it is larger than the sum of its proper divisors (214395).

643173 is a wasteful number, since it uses less digits than its factorization.

643173 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214394.

The product of its digits is 1512, while the sum is 24.

The square root of 643173 is about 801.9806730838. The cubic root of 643173 is about 86.3195699981.

The spelling of 643173 in words is "six hundred forty-three thousand, one hundred seventy-three".