28389409 has 2 divisors, whose sum is σ = 28389410. Its totient is φ = 28389408.

The previous prime is 28389407. The next prime is 28389467. The reversal of 28389409 is 90498382.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16160400 + 12229009 = 4020^2 + 3497^2 .

It is a cyclic number.

It is not a de Polignac number, because 28389409 - 2¹ = 28389407 is a prime.

Together with 28389407, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (28389407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14194704 + 14194705.

It is an arithmetic number, because the mean of its divisors is an integer number (14194705).

Almost surely, 2^28389409 is an apocalyptic number.

It is an amenable number.

28389409 is a deficient number, since it is larger than the sum of its proper divisors (1).

28389409 is an equidigital number, since it uses as much as digits as its factorization.

28389409 is an odious number, because the sum of its binary digits is odd.

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

The square root of 28389409 is about 5328.1712622625. The cubic root of 28389409 is about 305.0601296839.

The spelling of 28389409 in words is "twenty-eight million, three hundred eighty-nine thousand, four hundred nine".