11188991 has 12 divisors (see below), whose sum is σ = 12448800. Its totient is φ = 10047840.

The previous prime is 11188979. The next prime is 11188997. The reversal of 11188991 is 19988111.

It is not a de Polignac number, because 11188991 - 2¹⁴ = 11172607 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11188997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10250 + ... + 11288.

It is an arithmetic number, because the mean of its divisors is an integer number (1037400).

Almost surely, 2^11188991 is an apocalyptic number.

11188991 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

11188991 is a deficient number, since it is larger than the sum of its proper divisors (1259809).

11188991 is a wasteful number, since it uses less digits than its factorization.

11188991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1150 (or 1139 counting only the distinct ones).

The product of its digits is 5184, while the sum is 38.

The square root of 11188991 is about 3344.9949177839. The cubic root of 11188991 is about 223.6644569640.

The spelling of 11188991 in words is "eleven million, one hundred eighty-eight thousand, nine hundred ninety-one".