164809 has 2 divisors, whose sum is σ = 164810. Its totient is φ = 164808.

The previous prime is 164789. The next prime is 164821. The reversal of 164809 is 908461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 164025 + 784 = 405^2 + 28^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-164809 is a prime.

164809 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (164839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82404 + 82405.

It is an arithmetic number, because the mean of its divisors is an integer number (82405).

2¹⁶⁴⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

164809 is a deficient number, since it is larger than the sum of its proper divisors (1).

164809 is an equidigital number, since it uses as much as digits as its factorization.

164809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 164809 is about 405.9667474067. The cubic root of 164809 is about 54.8268937559.

The spelling of 164809 in words is "one hundred sixty-four thousand, eight hundred nine".