321221281 has 2 divisors, whose sum is σ = 321221282. Its totient is φ = 321221280.

The previous prime is 321221279. The next prime is 321221291. The reversal of 321221281 is 182122123.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 316270656 + 4950625 = 17784^2 + 2225^2 .

It is a cyclic number.

It is not a de Polignac number, because 321221281 - 2¹ = 321221279 is a prime.

It is a super-2 number, since 2×321221281² = 206366222734561922, which contains 22 as substring.

Together with 321221279, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (321221221) 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 as a sum of consecutive naturals, namely, 160610640 + 160610641.

It is an arithmetic number, because the mean of its divisors is an integer number (160610641).

Almost surely, 2^321221281 is an apocalyptic number.

It is an amenable number.

321221281 is a deficient number, since it is larger than the sum of its proper divisors (1).

321221281 is an equidigital number, since it uses as much as digits as its factorization.

321221281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 384, while the sum is 22.

The square root of 321221281 is about 17922.6471538107. The cubic root of 321221281 is about 684.8594245070.

The spelling of 321221281 in words is "three hundred twenty-one million, two hundred twenty-one thousand, two hundred eighty-one".