1103991 has 8 divisors (see below), whose sum is σ = 1682304. Its totient is φ = 630840.

The previous prime is 1103989. The next prime is 1104017. The reversal of 1103991 is 1993011.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1103991 - 2¹ = 1103989 is a prime.

It is a super-2 number, since 2×1103991² = 2437592256162, which contains 22 as substring.

1103991 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1103911) 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 in 7 ways as a sum of consecutive naturals, for example, 26265 + ... + 26306.

It is an arithmetic number, because the mean of its divisors is an integer number (210288).

2^1103991 is an apocalyptic number.

1103991 is a deficient number, since it is larger than the sum of its proper divisors (578313).

1103991 is an equidigital number, since it uses as much as digits as its factorization.

1103991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52581.

The product of its (nonzero) digits is 243, while the sum is 24.

The square root of 1103991 is about 1050.7097601146. The cubic root of 1103991 is about 103.3527041960.

The spelling of 1103991 in words is "one million, one hundred three thousand, nine hundred ninety-one".