1221202321 has 2 divisors, whose sum is σ = 1221202322. Its totient is φ = 1221202320.

The previous prime is 1221202291. The next prime is 1221202331. The reversal of 1221202321 is 1232021221.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 778689025 + 442513296 = 27905^2 + 21036^2 .

It is an emirp because it is prime and its reverse (1232021221) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1221202321 - 2¹¹ = 1221200273 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1221202295 and 1221202304.

It is not a weakly prime, because it can be changed into another prime (1221202331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610601160 + 610601161.

It is an arithmetic number, because the mean of its divisors is an integer number (610601161).

Almost surely, 2^1221202321 is an apocalyptic number.

It is an amenable number.

1221202321 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221202321 is an equidigital number, since it uses as much as digits as its factorization.

1221202321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 1221202321 is about 34945.7053298399. The cubic root of 1221202321 is about 1068.8806301302.

Adding to 1221202321 its reverse (1232021221), we get a palindrome (2453223542).

The spelling of 1221202321 in words is "one billion, two hundred twenty-one million, two hundred two thousand, three hundred twenty-one".