2101866 has 16 divisors (see below), whose sum is σ = 4527264. Its totient is φ = 646704.

The previous prime is 2101849. The next prime is 2101867. The reversal of 2101866 is 6681012.

It is not an unprimeable number, because it can be changed into a prime (2101867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13396 + ... + 13551.

It is an arithmetic number, because the mean of its divisors is an integer number (282954).

2^2101866 is an apocalyptic number.

2101866 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

2101866 is an abundant number, since it is smaller than the sum of its proper divisors (2425398).

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

2101866 is a wasteful number, since it uses less digits than its factorization.

2101866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26965.

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 2101866 is about 1449.7813628268. The cubic root of 2101866 is about 128.0958348052.

Adding to 2101866 its reverse (6681012), we get a palindrome (8782878).

The spelling of 2101866 in words is "two million, one hundred one thousand, eight hundred sixty-six".