28894309 has 4 divisors (see below), whose sum is σ = 28912716. Its totient is φ = 28875904.

The previous prime is 28894273. The next prime is 28894319. The reversal of 28894309 is 90349882.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 20930625 + 7963684 = 4575^2 + 2822^2 .

It is a cyclic number.

It is not a de Polignac number, because 28894309 - 2⁹ = 28893797 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 (28894319) 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 3 ways as a sum of consecutive naturals, for example, 6604 + ... + 10069.

It is an arithmetic number, because the mean of its divisors is an integer number (7228179).

Almost surely, 2^28894309 is an apocalyptic number.

It is an amenable number.

28894309 is a deficient number, since it is larger than the sum of its proper divisors (18407).

28894309 is a wasteful number, since it uses less digits than its factorization.

28894309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18406.

The product of its (nonzero) digits is 124416, while the sum is 43.

The square root of 28894309 is about 5375.3426867503. The cubic root of 28894309 is about 306.8579911706.

The spelling of 28894309 in words is "twenty-eight million, eight hundred ninety-four thousand, three hundred nine".