813811 has 2 divisors, whose sum is σ = 813812. Its totient is φ = 813810.

The previous prime is 813797. The next prime is 813817. The reversal of 813811 is 118318.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 813811 - 2⁹ = 813299 is a prime.

It is not a weakly prime, because it can be changed into another prime (813817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 406905 + 406906.

It is an arithmetic number, because the mean of its divisors is an integer number (406906).

2⁸¹³⁸¹¹ is an apocalyptic number.

813811 is a deficient number, since it is larger than the sum of its proper divisors (1).

813811 is an equidigital number, since it uses as much as digits as its factorization.

813811 is an evil number, because the sum of its binary digits is even.

The product of its digits is 192, while the sum is 22.

The square root of 813811 is about 902.1147377136. The cubic root of 813811 is about 93.3629398705.

The spelling of 813811 in words is "eight hundred thirteen thousand, eight hundred eleven".