851729 has 4 divisors (see below), whose sum is σ = 858084. Its totient is φ = 845376.

The previous prime is 851723. The next prime is 851731. The reversal of 851729 is 927158.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 927158 = 2 ⋅463579.

It can be written as a sum of positive squares in 2 ways, for example, as 565504 + 286225 = 752^2 + 535^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-851729 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 851695 and 851704.

It is not an unprimeable number, because it can be changed into a prime (851723) 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, 2972 + ... + 3245.

It is an arithmetic number, because the mean of its divisors is an integer number (214521).

2⁸⁵¹⁷²⁹ is an apocalyptic number.

It is an amenable number.

851729 is a deficient number, since it is larger than the sum of its proper divisors (6355).

851729 is a wasteful number, since it uses less digits than its factorization.

851729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6354.

The product of its digits is 5040, while the sum is 32.

The square root of 851729 is about 922.8916512787. The cubic root of 851729 is about 94.7910087196.

The spelling of 851729 in words is "eight hundred fifty-one thousand, seven hundred twenty-nine".