1221323221 has 8 divisors (see below), whose sum is σ = 1238365440. Its totient is φ = 1204380912.

The previous prime is 1221323203. The next prime is 1221323227. The reversal of 1221323221 is 1223231221.

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

It is a cyclic number.

It is not a de Polignac number, because 1221323221 - 2¹⁵ = 1221290453 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221323227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 190 + ... + 49423.

It is an arithmetic number, because the mean of its divisors is an integer number (154795680).

Almost surely, 2^1221323221 is an apocalyptic number.

It is an amenable number.

1221323221 is a deficient number, since it is larger than the sum of its proper divisors (17042219).

1221323221 is a wasteful number, since it uses less digits than its factorization.

1221323221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49955.

The product of its digits is 288, while the sum is 19.

The square root of 1221323221 is about 34947.4351133241. The cubic root of 1221323221 is about 1068.9159023101.

Adding to 1221323221 its reverse (1223231221), we get a palindrome (2444554442).

The spelling of 1221323221 in words is "one billion, two hundred twenty-one million, three hundred twenty-three thousand, two hundred twenty-one".