11181985 has 4 divisors (see below), whose sum is σ = 13418388. Its totient is φ = 8945584.

The previous prime is 11181959. The next prime is 11181991. The reversal of 11181985 is 58918111.

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

It can be written as a sum of positive squares in 2 ways, for example, as 5645376 + 5536609 = 2376^2 + 2353^2 .

It is a cyclic number.

It is not a de Polignac number, because 11181985 - 2⁵ = 11181953 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 11181985.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1118194 + ... + 1118203.

It is an arithmetic number, because the mean of its divisors is an integer number (3354597).

Almost surely, 2^11181985 is an apocalyptic number.

It is an amenable number.

11181985 is a deficient number, since it is larger than the sum of its proper divisors (2236403).

11181985 is an equidigital number, since it uses as much as digits as its factorization.

11181985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2236402.

The product of its digits is 2880, while the sum is 34.

The square root of 11181985 is about 3343.9475175307. The cubic root of 11181985 is about 223.6177646288.

The spelling of 11181985 in words is "eleven million, one hundred eighty-one thousand, nine hundred eighty-five".