28726409 has 2 divisors, whose sum is σ = 28726410. Its totient is φ = 28726408.

The previous prime is 28726403. The next prime is 28726421. The reversal of 28726409 is 90462782.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16581184 + 12145225 = 4072^2 + 3485^2 .

It is a cyclic number.

It is not a de Polignac number, because 28726409 - 2¹² = 28722313 is a prime.

It is not a weakly prime, because it can be changed into another prime (28726403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14363204 + 14363205.

It is an arithmetic number, because the mean of its divisors is an integer number (14363205).

Almost surely, 2^28726409 is an apocalyptic number.

It is an amenable number.

28726409 is a deficient number, since it is larger than the sum of its proper divisors (1).

28726409 is an equidigital number, since it uses as much as digits as its factorization.

28726409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48384, while the sum is 38.

The square root of 28726409 is about 5359.7023238236. The cubic root of 28726409 is about 306.2624693521.

The spelling of 28726409 in words is "twenty-eight million, seven hundred twenty-six thousand, four hundred nine".