1221451321 has 2 divisors, whose sum is σ = 1221451322. Its totient is φ = 1221451320.

The previous prime is 1221451313. The next prime is 1221451337. The reversal of 1221451321 is 1231541221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1091377296 + 130074025 = 33036^2 + 11405^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221451321 - 2³ = 1221451313 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1221451292 and 1221451301.

It is not a weakly prime, because it can be changed into another prime (1221451351) 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 as a sum of consecutive naturals, namely, 610725660 + 610725661.

It is an arithmetic number, because the mean of its divisors is an integer number (610725661).

Almost surely, 2^1221451321 is an apocalyptic number.

It is an amenable number.

1221451321 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221451321 is an equidigital number, since it uses as much as digits as its factorization.

1221451321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 480, while the sum is 22.

The square root of 1221451321 is about 34949.2678177956. The cubic root of 1221451321 is about 1068.9532725267.

Adding to 1221451321 its reverse (1231541221), we get a palindrome (2452992542).

The spelling of 1221451321 in words is "one billion, two hundred twenty-one million, four hundred fifty-one thousand, three hundred twenty-one".