2891 has 6 divisors (see below), whose sum is σ = 3420. Its totient is φ = 2436.

The previous prime is 2887. The next prime is 2897. The reversal of 2891 is 1982.

2891 = T_{28} + T_{29} + ... +
T_{33}.

2891 is nontrivially palindromic in base 16.

It is not a de Polignac number, because 2891 - 2^{2} = 2887 is a prime.

It is a Duffinian number.

2891 is an undulating number in base 16.

It is a nialpdrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (2897) 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 5 ways as a sum of consecutive naturals, for example, 20 + ... + 78.

It is an arithmetic number, because the mean of its divisors is an integer number (570).

2891 is a deficient number, since it is larger than the sum of its proper divisors (529).

2891 is an equidigital number, since it uses as much as digits as its factorization.

2891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73 (or 66 counting only the distinct ones).

The product of its digits is 144, while the sum is 20.

The square root of 2891 is about 53.7680202351. The cubic root of 2891 is about 14.2456640137.

Subtracting from 2891 its reverse (1982), we obtain a palindrome (909).

The spelling of 2891 in words is "two thousand, eight hundred ninety-one".

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