851831 has 2 divisors, whose sum is σ = 851832. Its totient is φ = 851830.

The previous prime is 851821. The next prime is 851839. The reversal of 851831 is 138158.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 851831 - 2¹⁰ = 850807 is a prime.

It is a super-2 number, since 2×851831² = 1451232105122, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 851831.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (851839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 425915 + 425916.

It is an arithmetic number, because the mean of its divisors is an integer number (425916).

2⁸⁵¹⁸³¹ is an apocalyptic number.

851831 is a deficient number, since it is larger than the sum of its proper divisors (1).

851831 is an equidigital number, since it uses as much as digits as its factorization.

851831 is an evil number, because the sum of its binary digits is even.

The product of its digits is 960, while the sum is 26.

The square root of 851831 is about 922.9469107159. The cubic root of 851831 is about 94.7947925119.

Adding to 851831 its reverse (138158), we get a palindrome (989989).

It can be divided in two parts, 85183 and 1, that added together give a cube (85184 = 44³).

The spelling of 851831 in words is "eight hundred fifty-one thousand, eight hundred thirty-one".