809129 has 4 divisors (see below), whose sum is σ = 837060. Its totient is φ = 781200.

The previous prime is 809101. The next prime is 809141. The reversal of 809129 is 921908.

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 597529 + 211600 = 773^2 + 460^2 .

It is a cyclic number.

It is not a de Polignac number, because 809129 - 2¹² = 805033 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29), and also a Moran number because the ratio is a prime number: 27901 = 809129 / (8 + 0 + 9 + 1 + 2 + 9).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (809189) 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, 13922 + ... + 13979.

It is an arithmetic number, because the mean of its divisors is an integer number (209265).

2⁸⁰⁹¹²⁹ is an apocalyptic number.

It is an amenable number.

809129 is a deficient number, since it is larger than the sum of its proper divisors (27931).

809129 is a wasteful number, since it uses less digits than its factorization.

809129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27930.

The product of its (nonzero) digits is 1296, while the sum is 29.

The square root of 809129 is about 899.5159809586. The cubic root of 809129 is about 93.1835508556.

The spelling of 809129 in words is "eight hundred nine thousand, one hundred twenty-nine".