1109 has 2 divisors, whose sum is σ = 1110. Its totient is φ = 1108.

The previous prime is 1103. The next prime is 1117. The reversal of 1109 is 9011.

1109 is nontrivially palindromic in base 11.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 625 + 484 = 25^2 + 22^2 .

It is an emirp because it is prime and its reverse (9011) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1109 - 2⁴ = 1093 is a prime.

It is a Chen prime.

1109 is an undulating number in base 11.

It is a plaindrome in base 15 and base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 1109.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1103) 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 as a sum of consecutive naturals, namely, 554 + 555.

It is an arithmetic number, because the mean of its divisors is an integer number (555).

It is an amenable number.

1109 is a deficient number, since it is larger than the sum of its proper divisors (1).

1109 is an equidigital number, since it uses as much as digits as its factorization.

1109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9, while the sum is 11.

The square root of 1109 is about 33.3016516107. The cubic root of 1109 is about 10.3508778146.

It can be divided in two parts, 110 and 9, that multiplied together give a triangular number (990 = T₄₄).

The spelling of 1109 in words is "one thousand, one hundred nine".