28066321 has 2 divisors, whose sum is σ = 28066322. Its totient is φ = 28066320.

The previous prime is 28066319. The next prime is 28066327. The reversal of 28066321 is 12366082.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15563025 + 12503296 = 3945^2 + 3536^2 .

It is a cyclic number.

It is not a de Polignac number, because 28066321 - 2¹ = 28066319 is a prime.

Together with 28066319, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28066321.

It is not a weakly prime, because it can be changed into another prime (28066327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14033160 + 14033161.

It is an arithmetic number, because the mean of its divisors is an integer number (14033161).

Almost surely, 2^28066321 is an apocalyptic number.

It is an amenable number.

28066321 is a deficient number, since it is larger than the sum of its proper divisors (1).

28066321 is an equidigital number, since it uses as much as digits as its factorization.

28066321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 28066321 is about 5297.7656611066. The cubic root of 28066321 is about 303.8984576897.

The spelling of 28066321 in words is "twenty-eight million, sixty-six thousand, three hundred twenty-one".