228821321 has 2 divisors, whose sum is σ = 228821322. Its totient is φ = 228821320.

The previous prime is 228821317. The next prime is 228821381. The reversal of 228821321 is 123128822.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 228765625 + 55696 = 15125^2 + 236^2 .

It is a cyclic number.

It is not a de Polignac number, because 228821321 - 2² = 228821317 is a prime.

It is not a weakly prime, because it can be changed into another prime (228821311) 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, 114410660 + 114410661.

It is an arithmetic number, because the mean of its divisors is an integer number (114410661).

Almost surely, 2^228821321 is an apocalyptic number.

It is an amenable number.

228821321 is a deficient number, since it is larger than the sum of its proper divisors (1).

228821321 is an equidigital number, since it uses as much as digits as its factorization.

228821321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3072, while the sum is 29.

The square root of 228821321 is about 15126.8410780308. The cubic root of 228821321 is about 611.6441544559.

The spelling of 228821321 in words is "two hundred twenty-eight million, eight hundred twenty-one thousand, three hundred twenty-one".