27428209 has 2 divisors, whose sum is σ = 27428210. Its totient is φ = 27428208.

The previous prime is 27428207. The next prime is 27428227. The reversal of 27428209 is 90282472.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25725184 + 1703025 = 5072^2 + 1305^2 .

It is a cyclic number.

It is not a de Polignac number, because 27428209 - 2¹ = 27428207 is a prime.

Together with 27428207, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (27428207) 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, 13714104 + 13714105.

It is an arithmetic number, because the mean of its divisors is an integer number (13714105).

Almost surely, 2^27428209 is an apocalyptic number.

It is an amenable number.

27428209 is a deficient number, since it is larger than the sum of its proper divisors (1).

27428209 is an equidigital number, since it uses as much as digits as its factorization.

27428209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16128, while the sum is 34.

The square root of 27428209 is about 5237.1947643753. The cubic root of 27428209 is about 301.5776481370.

The spelling of 27428209 in words is "twenty-seven million, four hundred twenty-eight thousand, two hundred nine".