28303309 has 2 divisors, whose sum is σ = 28303310. Its totient is φ = 28303308.

The previous prime is 28303291. The next prime is 28303313. The reversal of 28303309 is 90330382.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27071209 + 1232100 = 5203^2 + 1110^2 .

It is a cyclic number.

It is not a de Polignac number, because 28303309 - 2¹³ = 28295117 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28303109) 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, 14151654 + 14151655.

It is an arithmetic number, because the mean of its divisors is an integer number (14151655).

Almost surely, 2^28303309 is an apocalyptic number.

It is an amenable number.

28303309 is a deficient number, since it is larger than the sum of its proper divisors (1).

28303309 is an equidigital number, since it uses as much as digits as its factorization.

28303309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 28.

The square root of 28303309 is about 5320.0854316449. The cubic root of 28303309 is about 304.7514197817.

The spelling of 28303309 in words is "twenty-eight million, three hundred three thousand, three hundred nine".