811409 has 4 divisors (see below), whose sum is σ = 821760. Its totient is φ = 801060.

The previous prime is 811387. The next prime is 811411. The reversal of 811409 is 904118.

811409 = T₁₀₂ + T₁₀₃ + ... + T₁₈₀.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 811409 - 2¹⁶ = 745873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (811429) 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, 5057 + ... + 5214.

It is an arithmetic number, because the mean of its divisors is an integer number (205440).

2⁸¹¹⁴⁰⁹ is an apocalyptic number.

It is an amenable number.

811409 is a deficient number, since it is larger than the sum of its proper divisors (10351).

811409 is a wasteful number, since it uses less digits than its factorization.

811409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10350.

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 811409 is about 900.7824376618. The cubic root of 811409 is about 93.2709943697.

The spelling of 811409 in words is "eight hundred eleven thousand, four hundred nine".