810729 has 10 divisors (see below), whose sum is σ = 1211210. Its totient is φ = 540432.

The previous prime is 810697. The next prime is 810737. The reversal of 810729 is 927018.

It can be written as a sum of positive squares in only one way, i.e., 810000 + 729 = 900^2 + 27^2 .

It is not a de Polignac number, because 810729 - 2⁵ = 810697 is a prime.

It is a super-2 number, since 2×810729² = 1314563022882, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

810729 is a modest number, since divided by 729 gives 81 as remainder.

It is not an unprimeable number, because it can be changed into a prime (810769) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 4924 + ... + 5085.

It is an arithmetic number, because the mean of its divisors is an integer number (121121).

2⁸¹⁰⁷²⁹ is an apocalyptic number.

It is an amenable number.

810729 is a deficient number, since it is larger than the sum of its proper divisors (400481).

810729 is a wasteful number, since it uses less digits than its factorization.

810729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10021 (or 10012 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The square root of 810729 is about 900.4049089160. The cubic root of 810729 is about 93.2449318858.

The spelling of 810729 in words is "eight hundred ten thousand, seven hundred twenty-nine".