2185866 has 40 divisors (see below), whose sum is σ = 4983264. Its totient is φ = 716040.

The previous prime is 2185861. The next prime is 2185867. The reversal of 2185866 is 6685812.

It is a happy number.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 2185866.

It is not an unprimeable number, because it can be changed into a prime (2185861) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 16621 + ... + 16751.

2^2185866 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2185866, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2491632).

2185866 is an abundant number, since it is smaller than the sum of its proper divisors (2797398).

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

2185866 is a wasteful number, since it uses less digits than its factorization.

2185866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 248 (or 239 counting only the distinct ones).

The product of its digits is 23040, while the sum is 36.

The square root of 2185866 is about 1478.4674497601. The cubic root of 2185866 is about 129.7800224556.

It can be divided in two parts, 218 and 5866, that added together give a square (6084 = 78²).

The spelling of 2185866 in words is "two million, one hundred eighty-five thousand, eight hundred sixty-six".