11581065 has 24 divisors (see below), whose sum is σ = 20566728. Its totient is φ = 6024960.

The previous prime is 11581049. The next prime is 11581067. The reversal of 11581065 is 56018511.

It can be written as a sum of positive squares in 4 ways, for example, as 1411344 + 10169721 = 1188^2 + 3189^2 .

It is not a de Polignac number, because 11581065 - 2⁴ = 11581049 is a prime.

It is not an unprimeable number, because it can be changed into a prime (11581067) 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 23 ways as a sum of consecutive naturals, for example, 1294 + ... + 4983.

It is an arithmetic number, because the mean of its divisors is an integer number (856947).

Almost surely, 2^11581065 is an apocalyptic number.

11581065 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

11581065 is a deficient number, since it is larger than the sum of its proper divisors (8985663).

11581065 is a wasteful number, since it uses less digits than its factorization.

11581065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6329 (or 6326 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 27.

The square root of 11581065 is about 3403.0963841772. The cubic root of 11581065 is about 226.2470019850.

Adding to 11581065 its reverse (56018511), we get a palindrome (67599576).

The spelling of 11581065 in words is "eleven million, five hundred eighty-one thousand, sixty-five".