28564309 has 2 divisors, whose sum is σ = 28564310. Its totient is φ = 28564308.

The previous prime is 28564279. The next prime is 28564313. The reversal of 28564309 is 90346582.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22061809 + 6502500 = 4697^2 + 2550^2 .

It is a cyclic number.

It is not a de Polignac number, because 28564309 - 2¹⁵ = 28531541 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28564339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14282154 + 14282155.

It is an arithmetic number, because the mean of its divisors is an integer number (14282155).

Almost surely, 2^28564309 is an apocalyptic number.

It is an amenable number.

28564309 is a deficient number, since it is larger than the sum of its proper divisors (1).

28564309 is an equidigital number, since it uses as much as digits as its factorization.

28564309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 51840, while the sum is 37.

The square root of 28564309 is about 5344.5588218299. The cubic root of 28564309 is about 305.6853137824.

The spelling of 28564309 in words is "twenty-eight million, five hundred sixty-four thousand, three hundred nine".