28664309 has 2 divisors, whose sum is σ = 28664310. Its totient is φ = 28664308.

The previous prime is 28664303. The next prime is 28664341. The reversal of 28664309 is 90346682.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28143025 + 521284 = 5305^2 + 722^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28664309 is a prime.

It is a super-2 number, since 2×28664309² = 1643285220894962, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28664303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14332154 + 14332155.

It is an arithmetic number, because the mean of its divisors is an integer number (14332155).

Almost surely, 2^28664309 is an apocalyptic number.

It is an amenable number.

28664309 is a deficient number, since it is larger than the sum of its proper divisors (1).

28664309 is an equidigital number, since it uses as much as digits as its factorization.

28664309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 62208, while the sum is 38.

The square root of 28664309 is about 5353.9059573362. The cubic root of 28664309 is about 306.0416200669.

The spelling of 28664309 in words is "twenty-eight million, six hundred sixty-four thousand, three hundred nine".