11251221 has 4 divisors (see below), whose sum is σ = 15001632. Its totient is φ = 7500812.

The previous prime is 11251213. The next prime is 11251277. The reversal of 11251221 is 12215211.

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 11251221 - 2³ = 11251213 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 11251221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11251421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1875201 + ... + 1875206.

It is an arithmetic number, because the mean of its divisors is an integer number (3750408).

Almost surely, 2^11251221 is an apocalyptic number.

It is an amenable number.

11251221 is a deficient number, since it is larger than the sum of its proper divisors (3750411).

11251221 is an equidigital number, since it uses as much as digits as its factorization.

11251221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3750410.

The product of its digits is 40, while the sum is 15.

The square root of 11251221 is about 3354.2839772446. The cubic root of 11251221 is about 224.0783433979.

Adding to 11251221 its reverse (12215211), we get a palindrome (23466432).

It can be divided in two parts, 1125 and 1221, that added together give a triangular number (2346 = T₆₈).

The spelling of 11251221 in words is "eleven million, two hundred fifty-one thousand, two hundred twenty-one".