1224020321 has 6 divisors (see below), whose sum is σ = 1231421730. Its totient is φ = 1216663136.

The previous prime is 1224020269. The next prime is 1224020323. The reversal of 1224020321 is 1230204221.

It can be written as a sum of positive squares in only one way, i.e., 1206589696 + 17430625 = 34736^2 + 4175^2 .

It is not a de Polignac number, because 1224020321 - 2⁶ = 1224020257 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1224020321.

It is not an unprimeable number, because it can be changed into a prime (1224020323) 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 5 ways as a sum of consecutive naturals, for example, 5945 + ... + 49833.

It is an arithmetic number, because the mean of its divisors is an integer number (205236955).

Almost surely, 2^1224020321 is an apocalyptic number.

It is an amenable number.

1224020321 is a deficient number, since it is larger than the sum of its proper divisors (7401409).

1224020321 is an frugal number, since it uses more digits than its factorization.

1224020321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44223 (or 44056 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 1224020321 is about 34986.0017864288. The cubic root of 1224020321 is about 1069.7021679584.

Adding to 1224020321 its reverse (1230204221), we get a palindrome (2454224542).

The spelling of 1224020321 in words is "one billion, two hundred twenty-four million, twenty thousand, three hundred twenty-one".