2639 has 8 divisors (see below), whose sum is σ = 3360. Its totient is φ = 2016.

The previous prime is 2633. The next prime is 2647. The reversal of 2639 is 9362.

2639 = T₁₂ + T₁₃ + ... + T₂₅.

It is a happy number.

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

It is not a de Polignac number, because 2639 - 2⁸ = 2383 is a prime.

2639 is a modest number, since divided by 39 gives 26 as remainder.

It is a self number, because there is not a number n which added to its sum of digits gives 2639.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 77 + ... + 105.

It is an arithmetic number, because the mean of its divisors is an integer number (420).

2²⁶³⁹ is an apocalyptic number.

2639 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

2639 is a deficient number, since it is larger than the sum of its proper divisors (721).

2639 is a wasteful number, since it uses less digits than its factorization.

2639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49.

The product of its digits is 324, while the sum is 20.

The square root of 2639 is about 51.3711981562. The cubic root of 2639 is about 13.8191011833.

It can be divided in two parts, 263 and 9, that added together give a palindrome (272).

The spelling of 2639 in words is "two thousand, six hundred thirty-nine".