811729 has 2 divisors, whose sum is σ = 811730. Its totient is φ = 811728.

The previous prime is 811709. The next prime is 811747. The reversal of 811729 is 927118.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 748225 + 63504 = 865^2 + 252^2 .

It is a cyclic number.

It is not a de Polignac number, because 811729 - 2⁵ = 811697 is a prime.

It is a Chen prime.

811729 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 811697 and 811706.

It is not a weakly prime, because it can be changed into another prime (811709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 405864 + 405865.

It is an arithmetic number, because the mean of its divisors is an integer number (405865).

2⁸¹¹⁷²⁹ is an apocalyptic number.

It is an amenable number.

811729 is a deficient number, since it is larger than the sum of its proper divisors (1).

811729 is an equidigital number, since it uses as much as digits as its factorization.

811729 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1008, while the sum is 28.

The square root of 811729 is about 900.9600435091. The cubic root of 811729 is about 93.2832540297.

It can be divided in two parts, 811 and 729, that added together give a triangular number (1540 = T₅₅).

The spelling of 811729 in words is "eight hundred eleven thousand, seven hundred twenty-nine".