851851 has 32 divisors (see below), whose sum is σ = 1225728. Its totient is φ = 570240.

The previous prime is 851843. The next prime is 851863. The reversal of 851851 is 158158.

It is not a de Polignac number, because 851851 - 2³ = 851843 is a prime.

It is a Smith number, since the sum of its digits (28) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (851801) by changing a digit.

It is a Kaprekar number, because its square (725650126201) can be partitioned into two parts whose sum is 851851.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 23005 + ... + 23041.

It is an arithmetic number, because the mean of its divisors is an integer number (38304).

2⁸⁵¹⁸⁵¹ is an apocalyptic number.

851851 is a deficient number, since it is larger than the sum of its proper divisors (373877).

851851 is a wasteful number, since it uses less digits than its factorization.

851851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91.

The product of its digits is 1600, while the sum is 28.

The square root of 851851 is about 922.9577455117. The cubic root of 851851 is about 94.7955343965.

It can be divided in two parts, 85 and 1851, that added together give a square (1936 = 44²).

The spelling of 851851 in words is "eight hundred fifty-one thousand, eight hundred fifty-one".