11553221 has 4 divisors (see below), whose sum is σ = 11560032. Its totient is φ = 11546412.

The previous prime is 11553193. The next prime is 11553247. The reversal of 11553221 is 12235511.

It is a happy number.

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 a de Polignac number, because none of the positive numbers 2^k-11553221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 11553193 and 11553202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11556221) 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, 1400 + ... + 5006.

It is an arithmetic number, because the mean of its divisors is an integer number (2890008).

Almost surely, 2^11553221 is an apocalyptic number.

It is an amenable number.

11553221 is a deficient number, since it is larger than the sum of its proper divisors (6811).

11553221 is an equidigital number, since it uses as much as digits as its factorization.

11553221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6810.

The product of its digits is 300, while the sum is 20.

The square root of 11553221 is about 3399.0029420405. The cubic root of 11553221 is about 226.0655368970.

Subtracting from 11553221 its sum of digits (20), we obtain a square (11553201 = 3399²).

Adding to 11553221 its reverse (12235511), we get a palindrome (23788732).

The spelling of 11553221 in words is "eleven million, five hundred fifty-three thousand, two hundred twenty-one".