2691 has 12 divisors (see below), whose sum is σ = 4368. Its totient is φ = 1584.

The previous prime is 2689. The next prime is 2693. The reversal of 2691 is 1962.

It is an interprime number because it is at equal distance from previous prime (2689) and next prime (2693).

It is not a de Polignac number, because 2691 - 2¹ = 2689 is a prime.

It is a nialpdrome in base 14 and base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2693) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 106 + ... + 128.

It is an arithmetic number, because the mean of its divisors is an integer number (364).

2²⁶⁹¹ is an apocalyptic number.

2691 is a deficient number, since it is larger than the sum of its proper divisors (1677).

2691 is a wasteful number, since it uses less digits than its factorization.

2691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42 (or 39 counting only the distinct ones).

The product of its digits is 108, while the sum is 18.

The square root of 2691 is about 51.8748493974. The cubic root of 2691 is about 13.9092773151.

Subtracting from 2691 its reverse (1962), we obtain a 6-th power (729 = 3⁶).

The spelling of 2691 in words is "two thousand, six hundred ninety-one".