11509987 has 4 divisors (see below), whose sum is σ = 11527336. Its totient is φ = 11492640.

The previous prime is 11509973. The next prime is 11509999. The reversal of 11509987 is 78990511.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 11509987 - 2¹⁹ = 10985699 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11509387) by changing a digit.

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, 7638 + ... + 9019.

It is an arithmetic number, because the mean of its divisors is an integer number (2881834).

Almost surely, 2^11509987 is an apocalyptic number.

11509987 is a deficient number, since it is larger than the sum of its proper divisors (17349).

11509987 is an equidigital number, since it uses as much as digits as its factorization.

11509987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17348.

The product of its (nonzero) digits is 22680, while the sum is 40.

The square root of 11509987 is about 3392.6371748243. The cubic root of 11509987 is about 225.7831932852.

The spelling of 11509987 in words is "eleven million, five hundred nine thousand, nine hundred eighty-seven".