11003561 has 4 divisors (see below), whose sum is σ = 11010432. Its totient is φ = 10996692.

The previous prime is 11003549. The next prime is 11003563. The reversal of 11003561 is 16530011.

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 11003561 - 2⁶ = 11003497 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 (11003563) 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, 380 + ... + 4706.

It is an arithmetic number, because the mean of its divisors is an integer number (2752608).

Almost surely, 2^11003561 is an apocalyptic number.

It is an amenable number.

11003561 is a deficient number, since it is larger than the sum of its proper divisors (6871).

11003561 is an equidigital number, since it uses as much as digits as its factorization.

11003561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6870.

The product of its (nonzero) digits is 90, while the sum is 17.

The square root of 11003561 is about 3317.1615878639. The cubic root of 11003561 is about 222.4220052347.

Adding to 11003561 its reverse (16530011), we get a palindrome (27533572).

The spelling of 11003561 in words is "eleven million, three thousand, five hundred sixty-one".