643271 has 4 divisors (see below), whose sum is σ = 646032. Its totient is φ = 640512.

The previous prime is 643243. The next prime is 643273. The reversal of 643271 is 172346.

643271 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 643271 - 2¹⁰ = 642247 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643273) 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, 995 + ... + 1508.

It is an arithmetic number, because the mean of its divisors is an integer number (161508).

2⁶⁴³²⁷¹ is an apocalyptic number.

643271 is a deficient number, since it is larger than the sum of its proper divisors (2761).

643271 is a wasteful number, since it uses less digits than its factorization.

643271 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2760.

The product of its digits is 1008, while the sum is 23.

The square root of 643271 is about 802.0417694859. The cubic root of 643271 is about 86.3239539343.

The spelling of 643271 in words is "six hundred forty-three thousand, two hundred seventy-one".