811841 has 4 divisors (see below), whose sum is σ = 831684. Its totient is φ = 792000.

The previous prime is 811819. The next prime is 811861. The reversal of 811841 is 148118.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 10816 + 801025 = 104^2 + 895^2 .

It is a cyclic number.

It is not a de Polignac number, because 811841 - 2⁶ = 811777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (811861) 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, 9860 + ... + 9941.

It is an arithmetic number, because the mean of its divisors is an integer number (207921).

2⁸¹¹⁸⁴¹ is an apocalyptic number.

It is an amenable number.

811841 is a deficient number, since it is larger than the sum of its proper divisors (19843).

811841 is a wasteful number, since it uses less digits than its factorization.

811841 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19842.

The product of its digits is 256, while the sum is 23.

The square root of 811841 is about 901.0221972848. The cubic root of 811841 is about 93.2875441496.

Adding to 811841 its reverse (148118), we get a palindrome (959959).

The spelling of 811841 in words is "eight hundred eleven thousand, eight hundred forty-one".