11521409 has 4 divisors (see below), whose sum is σ = 11627220. Its totient is φ = 11415600.

The previous prime is 11521379. The next prime is 11521421. The reversal of 11521409 is 90412511.

It is a happy number.

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 4906225 + 6615184 = 2215^2 + 2572^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11521409 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (11521709) 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, 52742 + ... + 52959.

It is an arithmetic number, because the mean of its divisors is an integer number (2906805).

Almost surely, 2^11521409 is an apocalyptic number.

It is an amenable number.

11521409 is a deficient number, since it is larger than the sum of its proper divisors (105811).

11521409 is a wasteful number, since it uses less digits than its factorization.

11521409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105810.

The product of its (nonzero) digits is 360, while the sum is 23.

The square root of 11521409 is about 3394.3201086521. The cubic root of 11521409 is about 225.8578543322.

The spelling of 11521409 in words is "eleven million, five hundred twenty-one thousand, four hundred nine".