28860309 has 6 divisors (see below), whose sum is σ = 41687126. Its totient is φ = 19240200.

The previous prime is 28860289. The next prime is 28860311. The reversal of 28860309 is 90306882.

It can be written as a sum of positive squares in only one way, i.e., 28836900 + 23409 = 5370^2 + 153^2 .

It is not a de Polignac number, because 28860309 - 2⁹ = 28859797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28860389) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1603342 + ... + 1603359.

Almost surely, 2^28860309 is an apocalyptic number.

It is an amenable number.

28860309 is a deficient number, since it is larger than the sum of its proper divisors (12826817).

28860309 is a wasteful number, since it uses less digits than its factorization.

28860309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3206707 (or 3206704 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 28860309 is about 5372.1791667814. The cubic root of 28860309 is about 306.7375837618.

The spelling of 28860309 in words is "twenty-eight million, eight hundred sixty thousand, three hundred nine".