1109891 has 2 divisors, whose sum is σ = 1109892. Its totient is φ = 1109890.

The previous prime is 1109887. The next prime is 1109897. The reversal of 1109891 is 1989011.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1109891 - 2² = 1109887 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1109897) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 554945 + 554946.

It is an arithmetic number, because the mean of its divisors is an integer number (554946).

2^1109891 is an apocalyptic number.

1109891 is a deficient number, since it is larger than the sum of its proper divisors (1).

1109891 is an equidigital number, since it uses as much as digits as its factorization.

1109891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 648, while the sum is 29.

The square root of 1109891 is about 1053.5136449045. The cubic root of 1109891 is about 103.5364912907.

It can be divided in two parts, 110 and 9891, that added together give a palindrome (10001).

The spelling of 1109891 in words is "one million, one hundred nine thousand, eight hundred ninety-one".