1100991 has 4 divisors (see below), whose sum is σ = 1467992. Its totient is φ = 733992.

The previous prime is 1100977. The next prime is 1101071. The reversal of 1100991 is 1990011.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1100991 - 2¹⁷ = 969919 is a prime.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1100921) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 183496 + ... + 183501.

It is an arithmetic number, because the mean of its divisors is an integer number (366998).

2^1100991 is an apocalyptic number.

1100991 is a deficient number, since it is larger than the sum of its proper divisors (367001).

1100991 is an equidigital number, since it uses as much as digits as its factorization.

1100991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 367000.

The product of its (nonzero) digits is 81, while the sum is 21.

The square root of 1100991 is about 1049.2811825245. The cubic root of 1100991 is about 103.2590019257.

The spelling of 1100991 in words is "one million, one hundred thousand, nine hundred ninety-one".