11518561 has 4 divisors (see below), whose sum is σ = 12019392. Its totient is φ = 11017732.

The previous prime is 11518553. The next prime is 11518583. The reversal of 11518561 is 16581511.

11518561 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, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16581511 = 17 ⋅975383.

It is a cyclic number.

It is not a de Polignac number, because 11518561 - 2³ = 11518553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11518501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 250381 + ... + 250426.

It is an arithmetic number, because the mean of its divisors is an integer number (3004848).

Almost surely, 2^11518561 is an apocalyptic number.

It is an amenable number.

11518561 is a deficient number, since it is larger than the sum of its proper divisors (500831).

11518561 is an equidigital number, since it uses as much as digits as its factorization.

11518561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 500830.

The product of its digits is 1200, while the sum is 28.

The square root of 11518561 is about 3393.9005583546. The cubic root of 11518561 is about 225.8392427145.

The spelling of 11518561 in words is "eleven million, five hundred eighteen thousand, five hundred sixty-one".