11015561 has 4 divisors (see below), whose sum is σ = 11025792. Its totient is φ = 11005332.

The previous prime is 11015539. The next prime is 11015581. The reversal of 11015561 is 16551011.

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 a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 11015561 - 2¹⁰ = 11014537 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 (11015581) 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, 3281 + ... + 5726.

It is an arithmetic number, because the mean of its divisors is an integer number (2756448).

Almost surely, 2^11015561 is an apocalyptic number.

It is an amenable number.

11015561 is a deficient number, since it is larger than the sum of its proper divisors (10231).

11015561 is an equidigital number, since it uses as much as digits as its factorization.

11015561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10230.

The product of its (nonzero) digits is 150, while the sum is 20.

The square root of 11015561 is about 3318.9698703061. The cubic root of 11015561 is about 222.5028304147.

Adding to 11015561 its reverse (16551011), we get a palindrome (27566572).

The spelling of 11015561 in words is "eleven million, fifteen thousand, five hundred sixty-one".