11555521 has 4 divisors (see below), whose sum is σ = 11570992. Its totient is φ = 11540052.

The previous prime is 11555501. The next prime is 11555549. The reversal of 11555521 is 12555511.

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.

It is a cyclic number.

It is not a de Polignac number, because 11555521 - 2⁹ = 11555009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11555501) 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, 6555 + ... + 8128.

It is an arithmetic number, because the mean of its divisors is an integer number (2892748).

Almost surely, 2^11555521 is an apocalyptic number.

It is an amenable number.

11555521 is a deficient number, since it is larger than the sum of its proper divisors (15471).

11555521 is an equidigital number, since it uses as much as digits as its factorization.

11555521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15470.

The product of its digits is 1250, while the sum is 25.

The square root of 11555521 is about 3399.3412597149. The cubic root of 11555521 is about 226.0805375112.

The spelling of 11555521 in words is "eleven million, five hundred fifty-five thousand, five hundred twenty-one".