851881 has 2 divisors, whose sum is σ = 851882. Its totient is φ = 851880.

The previous prime is 851863. The next prime is 851891. The reversal of 851881 is 188158.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 826281 + 25600 = 909^2 + 160^2 .

It is a cyclic number.

It is not a de Polignac number, because 851881 - 2¹¹ = 849833 is a prime.

It is a super-2 number, since 2×851881² = 1451402476322, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (851801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 425940 + 425941.

It is an arithmetic number, because the mean of its divisors is an integer number (425941).

2⁸⁵¹⁸⁸¹ is an apocalyptic number.

It is an amenable number.

851881 is a deficient number, since it is larger than the sum of its proper divisors (1).

851881 is an equidigital number, since it uses as much as digits as its factorization.

851881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2560, while the sum is 31.

The square root of 851881 is about 922.9739974669. The cubic root of 851881 is about 94.7966472017.

The spelling of 851881 in words is "eight hundred fifty-one thousand, eight hundred eighty-one".