12311221 has 8 divisors (see below), whose sum is σ = 13956320. Its totient is φ = 10765872.

The previous prime is 12311219. The next prime is 12311251. The reversal of 12311221 is 12211321.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 12311221 - 2¹ = 12311219 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12311251) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24675 + ... + 25168.

It is an arithmetic number, because the mean of its divisors is an integer number (1744540).

Almost surely, 2^12311221 is an apocalyptic number.

It is an amenable number.

12311221 is a deficient number, since it is larger than the sum of its proper divisors (1645099).

12311221 is a wasteful number, since it uses less digits than its factorization.

12311221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49875.

The product of its digits is 24, while the sum is 13.

The square root of 12311221 is about 3508.7349572175. The cubic root of 12311221 is about 230.9051977570.

Adding to 12311221 its reverse (12211321), we get a palindrome (24522542).

It can be divided in two parts, 1231 and 1221, that multiplied together give a palindrome (1503051).

The spelling of 12311221 in words is "twelve million, three hundred eleven thousand, two hundred twenty-one".