2649 has 4 divisors (see below), whose sum is σ = 3536. Its totient is φ = 1764.

The previous prime is 2647. The next prime is 2657. The reversal of 2649 is 9462.

2649 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, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 2649 - 2¹ = 2647 is a prime.

It is a D-number.

It is a Duffinian number.

2649 is a lucky number.

It is a plaindrome in base 13.

It is a nialpdrome in base 14 and base 15.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 2649.

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, 439 + ... + 444.

It is an arithmetic number, because the mean of its divisors is an integer number (884).

2²⁶⁴⁹ is an apocalyptic number.

It is an amenable number.

2649 is a deficient number, since it is larger than the sum of its proper divisors (887).

2649 is an equidigital number, since it uses as much as digits as its factorization.

2649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 886.

The product of its digits is 432, while the sum is 21.

The square root of 2649 is about 51.4684369298. The cubic root of 2649 is about 13.8365341539.

Subtracting from 2649 its sum of digits (21), we obtain a triangular number (2628 = T₇₂).

Adding to 2649 its product of digits (432), we get a triangular number (3081 = T₇₈).

The spelling of 2649 in words is "two thousand, six hundred forty-nine".