10985809 has 4 divisors (see below), whose sum is σ = 11364660. Its totient is φ = 10606960.

The previous prime is 10985803. The next prime is 10985813. The reversal of 10985809 is 90858901.

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 4635409 + 6350400 = 2153^2 + 2520^2 .

It is a cyclic number.

It is not a de Polignac number, because 10985809 - 2⁹ = 10985297 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (10985803) 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 3 ways as a sum of consecutive naturals, for example, 189382 + ... + 189439.

It is an arithmetic number, because the mean of its divisors is an integer number (2841165).

Almost surely, 2^10985809 is an apocalyptic number.

It is an amenable number.

10985809 is a deficient number, since it is larger than the sum of its proper divisors (378851).

10985809 is an equidigital number, since it uses as much as digits as its factorization.

10985809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 378850.

The product of its (nonzero) digits is 25920, while the sum is 40.

The square root of 10985809 is about 3314.4847261679. The cubic root of 10985809 is about 222.3023300170.

The spelling of 10985809 in words is "ten million, nine hundred eighty-five thousand, eight hundred nine".