17791 has 2 divisors, whose sum is σ = 17792. Its totient is φ = 17790.

The previous prime is 17789. The next prime is 17807. The reversal of 17791 is 19771.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 17791 - 2¹ = 17789 is a prime.

Together with 17789, it forms a pair of twin primes.

It is a plaindrome in base 14 and base 16.

It is a nialpdrome in base 15.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (17761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8895 + 8896.

It is an arithmetic number, because the mean of its divisors is an integer number (8896).

2¹⁷⁷⁹¹ is an apocalyptic number.

17791 is a deficient number, since it is larger than the sum of its proper divisors (1).

17791 is an equidigital number, since it uses as much as digits as its factorization.

17791 is an evil number, because the sum of its binary digits is even.

The product of its digits is 441, while the sum is 25.

The square root of 17791 is about 133.3829074507. The cubic root of 17791 is about 26.1055864106.

Subtracting from 17791 its sum of digits (25), we obtain a triangular number (17766 = T₁₈₈).

It can be divided in two parts, 17 and 791, that added together give a palindrome (808).

The spelling of 17791 in words is "seventeen thousand, seven hundred ninety-one".