851868 has 18 divisors (see below), whose sum is σ = 2153424. Its totient is φ = 283944.

The previous prime is 851863. The next prime is 851881. The reversal of 851868 is 868158.

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 23663 = 851868 / (8 + 5 + 1 + 8 + 6 + 8).

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (851863) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11796 + ... + 11867.

2⁸⁵¹⁸⁶⁸ is an apocalyptic number.

It is an amenable number.

851868 is an abundant number, since it is smaller than the sum of its proper divisors (1301556).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

851868 is a wasteful number, since it uses less digits than its factorization.

851868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23673 (or 23668 counting only the distinct ones).

The product of its digits is 15360, while the sum is 36.

The square root of 851868 is about 922.9669549881. The cubic root of 851868 is about 94.7961649893.

Subtracting 851868 from its reverse (868158), we obtain a triangular number (16290 = T₁₈₀).

It can be divided in two parts, 85 and 1868, that added together give a triangular number (1953 = T₆₂).

The spelling of 851868 in words is "eight hundred fifty-one thousand, eight hundred sixty-eight".