28928300221 has 2 divisors, whose sum is σ = 28928300222. Its totient is φ = 28928300220.

The previous prime is 28928300201. The next prime is 28928300243. The reversal of 28928300221 is 12200382982.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28684503225 + 243796996 = 169365^2 + 15614^2 .

It is a cyclic number.

It is not a de Polignac number, because 28928300221 - 2¹¹ = 28928298173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28928300201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14464150110 + 14464150111.

It is an arithmetic number, because the mean of its divisors is an integer number (14464150111).

Almost surely, 2^28928300221 is an apocalyptic number.

It is an amenable number.

28928300221 is a deficient number, since it is larger than the sum of its proper divisors (1).

28928300221 is an equidigital number, since it uses as much as digits as its factorization.

28928300221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27648, while the sum is 37.

The spelling of 28928300221 in words is "twenty-eight billion, nine hundred twenty-eight million, three hundred thousand, two hundred twenty-one".