28556321 has 2 divisors, whose sum is σ = 28556322. Its totient is φ = 28556320.

The previous prime is 28556303. The next prime is 28556371. The reversal of 28556321 is 12365582.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19936225 + 8620096 = 4465^2 + 2936^2 .

It is a cyclic number.

It is not a de Polignac number, because 28556321 - 2¹⁸ = 28294177 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28556371) 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, 14278160 + 14278161.

It is an arithmetic number, because the mean of its divisors is an integer number (14278161).

Almost surely, 2^28556321 is an apocalyptic number.

It is an amenable number.

28556321 is a deficient number, since it is larger than the sum of its proper divisors (1).

28556321 is an equidigital number, since it uses as much as digits as its factorization.

28556321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14400, while the sum is 32.

The square root of 28556321 is about 5343.8114674827. The cubic root of 28556321 is about 305.6568161920.

The spelling of 28556321 in words is "twenty-eight million, five hundred fifty-six thousand, three hundred twenty-one".