84509 has 2 divisors, whose sum is σ = 84510. Its totient is φ = 84508.

The previous prime is 84503. The next prime is 84521. The reversal of 84509 is 90548.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 77284 + 7225 = 278^2 + 85^2 .

It is a cyclic number.

It is not a de Polignac number, because 84509 - 2¹⁶ = 18973 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42254 + 42255.

It is an arithmetic number, because the mean of its divisors is an integer number (42255).

2⁸⁴⁵⁰⁹ is an apocalyptic number.

It is an amenable number.

84509 is a deficient number, since it is larger than the sum of its proper divisors (1).

84509 is an equidigital number, since it uses as much as digits as its factorization.

84509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 84509 is about 290.7043171334. The cubic root of 84509 is about 43.8834726591.

The spelling of 84509 in words is "eighty-four thousand, five hundred nine".