11509865 has 4 divisors (see below), whose sum is σ = 13811844. Its totient is φ = 9207888.

The previous prime is 11509843. The next prime is 11509871. The reversal of 11509865 is 56890511.

11509865 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 6370576 + 5139289 = 2524^2 + 2267^2 .

It is a cyclic number.

It is not a de Polignac number, because 11509865 - 2¹⁰ = 11508841 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1150982 + ... + 1150991.

It is an arithmetic number, because the mean of its divisors is an integer number (3452961).

Almost surely, 2^11509865 is an apocalyptic number.

It is an amenable number.

11509865 is a deficient number, since it is larger than the sum of its proper divisors (2301979).

11509865 is an equidigital number, since it uses as much as digits as its factorization.

11509865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2301978.

The product of its (nonzero) digits is 10800, while the sum is 35.

The square root of 11509865 is about 3392.6191946636. The cubic root of 11509865 is about 225.7823955534.

The spelling of 11509865 in words is "eleven million, five hundred nine thousand, eight hundred sixty-five".