28707409 has 2 divisors, whose sum is σ = 28707410. Its totient is φ = 28707408.

The previous prime is 28707401. The next prime is 28707433. The reversal of 28707409 is 90470782.

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., 28569025 + 138384 = 5345^2 + 372^2 .

It is a cyclic number.

It is not a de Polignac number, because 28707409 - 2³ = 28707401 is a prime.

It is not a weakly prime, because it can be changed into another prime (28707401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14353704 + 14353705.

It is an arithmetic number, because the mean of its divisors is an integer number (14353705).

Almost surely, 2^28707409 is an apocalyptic number.

It is an amenable number.

28707409 is a deficient number, since it is larger than the sum of its proper divisors (1).

28707409 is an equidigital number, since it uses as much as digits as its factorization.

28707409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 28224, while the sum is 37.

The square root of 28707409 is about 5357.9295441430. The cubic root of 28707409 is about 306.1949325394.

The spelling of 28707409 in words is "twenty-eight million, seven hundred seven thousand, four hundred nine".