851971 has 2 divisors, whose sum is σ = 851972. Its totient is φ = 851970.

The previous prime is 851957. The next prime is 852011. The reversal of 851971 is 179158.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 851971 - 2⁷ = 851843 is a prime.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (851171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 425985 + 425986.

It is an arithmetic number, because the mean of its divisors is an integer number (425986).

2⁸⁵¹⁹⁷¹ is an apocalyptic number.

851971 is a deficient number, since it is larger than the sum of its proper divisors (1).

851971 is an equidigital number, since it uses as much as digits as its factorization.

851971 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2520, while the sum is 31.

The square root of 851971 is about 923.0227516156. The cubic root of 851971 is about 94.7999854605.

The spelling of 851971 in words is "eight hundred fifty-one thousand, nine hundred seventy-one".