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28409 is a prime number
BaseRepresentation
bin110111011111001
31102222012
412323321
51402114
6335305
7145553
oct67371
942865
1028409
111a387
1214535
13cc14
14a4d3
15863e
hex6ef9

28409 has 2 divisors, whose sum is σ = 28410. Its totient is φ = 28408.

The previous prime is 28403. The next prime is 28411. The reversal of 28409 is 90482.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25600 + 2809 = 160^2 + 53^2 .

It is a cyclic number.

It is not a de Polignac number, because 28409 - 24 = 28393 is a prime.

Together with 28411, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28403) 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, 14204 + 14205.

It is an arithmetic number, because the mean of its divisors is an integer number (14205).

228409 is an apocalyptic number.

It is an amenable number.

28409 is a deficient number, since it is larger than the sum of its proper divisors (1).

28409 is an equidigital number, since it uses as much as digits as its factorization.

28409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 28409 is about 168.5496959356. The cubic root of 28409 is about 30.5130285645.

The spelling of 28409 in words is "twenty-eight thousand, four hundred nine".