27989009 has 2 divisors, whose sum is σ = 27989010. Its totient is φ = 27989008.

The previous prime is 27988991. The next prime is 27989041. The reversal of 27989009 is 90098972.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25654225 + 2334784 = 5065^2 + 1528^2 .

It is a cyclic number.

It is not a de Polignac number, because 27989009 - 2²⁴ = 11211793 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (27989609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13994504 + 13994505.

It is an arithmetic number, because the mean of its divisors is an integer number (13994505).

Almost surely, 2^27989009 is an apocalyptic number.

It is an amenable number.

27989009 is a deficient number, since it is larger than the sum of its proper divisors (1).

27989009 is an equidigital number, since it uses as much as digits as its factorization.

27989009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 81648, while the sum is 44.

The square root of 27989009 is about 5290.4639683113. The cubic root of 27989009 is about 303.6191596669.

The spelling of 27989009 in words is "twenty-seven million, nine hundred eighty-nine thousand, nine".