855409 has 4 divisors (see below), whose sum is σ = 861300. Its totient is φ = 849520.

The previous prime is 855401. The next prime is 855419. The reversal of 855409 is 904558.

855409 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 904558 = 2 ⋅452279.

It can be written as a sum of positive squares in 2 ways, for example, as 247009 + 608400 = 497^2 + 780^2 .

It is a cyclic number.

It is not a de Polignac number, because 855409 - 2³ = 855401 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (855401) 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, 2722 + ... + 3019.

It is an arithmetic number, because the mean of its divisors is an integer number (215325).

2⁸⁵⁵⁴⁰⁹ is an apocalyptic number.

It is an amenable number.

855409 is a deficient number, since it is larger than the sum of its proper divisors (5891).

855409 is a wasteful number, since it uses less digits than its factorization.

855409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5890.

The product of its (nonzero) digits is 7200, while the sum is 31.

The square root of 855409 is about 924.8832358736. The cubic root of 855409 is about 94.9273313157.

The spelling of 855409 in words is "eight hundred fifty-five thousand, four hundred nine".