2643 has 4 divisors (see below), whose sum is σ = 3528. Its totient is φ = 1760.

The previous prime is 2633. The next prime is 2647. The reversal of 2643 is 3462.

Added to its reverse (3462) it gives a triangular number (6105 = T₁₁₀).

2643 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 2643 - 2⁶ = 2579 is a prime.

It is a D-number.

It is a plaindrome in base 9.

It is a nialpdrome in base 15 and base 16.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 2643.

It is not an unprimeable number, because it can be changed into a prime (2647) 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, 438 + ... + 443.

It is an arithmetic number, because the mean of its divisors is an integer number (882).

2²⁶⁴³ is an apocalyptic number.

2643 is a deficient number, since it is larger than the sum of its proper divisors (885).

2643 is an equidigital number, since it uses as much as digits as its factorization.

2643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 884.

The product of its digits is 144, while the sum is 15.

The square root of 2643 is about 51.4101157361. The cubic root of 2643 is about 13.8260796474.

Subtracting from 2643 its sum of digits (15), we obtain a triangular number (2628 = T₇₂).

Adding to 2643 its reverse (3462), we get a triangular number (6105 = T₁₁₀).

The spelling of 2643 in words is "two thousand, six hundred forty-three".