854809 has 4 divisors (see below), whose sum is σ = 875700. Its totient is φ = 833920.

The previous prime is 854807. The next prime is 854849. The reversal of 854809 is 908458.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 908458 = 2 ⋅454229.

It can be written as a sum of positive squares in 2 ways, for example, as 403225 + 451584 = 635^2 + 672^2 .

It is a cyclic number.

It is not a de Polignac number, because 854809 - 2¹ = 854807 is a prime.

It is a Duffinian number.

854809 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (854801) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10384 + ... + 10465.

It is an arithmetic number, because the mean of its divisors is an integer number (218925).

2⁸⁵⁴⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

854809 is a deficient number, since it is larger than the sum of its proper divisors (20891).

854809 is a wasteful number, since it uses less digits than its factorization.

854809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20890.

The product of its (nonzero) digits is 11520, while the sum is 34.

The square root of 854809 is about 924.5588137052. The cubic root of 854809 is about 94.9051315178.

The spelling of 854809 in words is "eight hundred fifty-four thousand, eight hundred nine".