857851 has 2 divisors, whose sum is σ = 857852. Its totient is φ = 857850.

The previous prime is 857839. The next prime is 857867. The reversal of 857851 is 158758.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 857851 - 2⁷ = 857723 is a prime.

It is not a weakly prime, because it can be changed into another prime (857821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 428925 + 428926.

It is an arithmetic number, because the mean of its divisors is an integer number (428926).

2⁸⁵⁷⁸⁵¹ is an apocalyptic number.

857851 is a deficient number, since it is larger than the sum of its proper divisors (1).

857851 is an equidigital number, since it uses as much as digits as its factorization.

857851 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11200, while the sum is 34.

The square root of 857851 is about 926.2024616681. The cubic root of 857851 is about 95.0175775416.

The spelling of 857851 in words is "eight hundred fifty-seven thousand, eight hundred fifty-one".