28298309 has 8 divisors (see below), whose sum is σ = 30699480. Its totient is φ = 25929216.

The previous prime is 28298299. The next prime is 28298311. The reversal of 28298309 is 90389282.

It can be written as a sum of positive squares in 4 ways, for example, as 240100 + 28058209 = 490^2 + 5297^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28298309 - 2⁴ = 28298293 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28298359) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6164 + ... + 9725.

It is an arithmetic number, because the mean of its divisors is an integer number (3837435).

Almost surely, 2^28298309 is an apocalyptic number.

It is an amenable number.

28298309 is a deficient number, since it is larger than the sum of its proper divisors (2401171).

28298309 is a wasteful number, since it uses less digits than its factorization.

28298309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16039.

The product of its (nonzero) digits is 62208, while the sum is 41.

The square root of 28298309 is about 5319.6154936236. The cubic root of 28298309 is about 304.7334731541.

The spelling of 28298309 in words is "twenty-eight million, two hundred ninety-eight thousand, three hundred nine".