28500309 has 8 divisors (see below), whose sum is σ = 42222720. Its totient is φ = 19000188.

The previous prime is 28500299. The next prime is 28500317. The reversal of 28500309 is 90300582.

It is not a de Polignac number, because 28500309 - 2²⁴ = 11723093 is a prime.

It is a super-2 number, since 2×28500309² = 1624535226190962, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 1055567 = 28500309 / (2 + 8 + 5 + 0 + 0 + 3 + 0 + 9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28500349) 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 in 7 ways as a sum of consecutive naturals, for example, 527757 + ... + 527810.

It is an arithmetic number, because the mean of its divisors is an integer number (5277840).

Almost surely, 2^28500309 is an apocalyptic number.

It is an amenable number.

28500309 is a deficient number, since it is larger than the sum of its proper divisors (13722411).

28500309 is a wasteful number, since it uses less digits than its factorization.

28500309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1055576 (or 1055570 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 28500309 is about 5338.5680664388. The cubic root of 28500309 is about 305.4568411382.

The spelling of 28500309 in words is "twenty-eight million, five hundred thousand, three hundred nine".