28306305 has 12 divisors (see below), whose sum is σ = 49064340. Its totient is φ = 15096672.

The previous prime is 28306303. The next prime is 28306337. The reversal of 28306305 is 50360382.

28306305 is a `hidden beast` number, since 28 + 3 + 0 + 630 + 5 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 12362256 + 15944049 = 3516^2 + 3993^2 .

It is not a de Polignac number, because 28306305 - 2¹ = 28306303 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28306301) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 314470 + ... + 314559.

It is an arithmetic number, because the mean of its divisors is an integer number (4088695).

Almost surely, 2^28306305 is an apocalyptic number.

It is an amenable number.

28306305 is a deficient number, since it is larger than the sum of its proper divisors (20758035).

28306305 is a wasteful number, since it uses less digits than its factorization.

28306305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 629040 (or 629037 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 28306305 is about 5320.3669986196. The cubic root of 28306305 is about 304.7621723882.

Adding to 28306305 its reverse (50360382), we get a palindrome (78666687).

The spelling of 28306305 in words is "twenty-eight million, three hundred six thousand, three hundred five".