2181868 has 12 divisors (see below), whose sum is σ = 4112080. Its totient is φ = 1006992.

The previous prime is 2181857. The next prime is 2181869. The reversal of 2181868 is 8681812.

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (2181869) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20928 + ... + 21031.

2^2181868 is an apocalyptic number.

It is an amenable number.

2181868 is a deficient number, since it is larger than the sum of its proper divisors (1930212).

2181868 is a wasteful number, since it uses less digits than its factorization.

2181868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41976 (or 41974 counting only the distinct ones).

The product of its digits is 6144, while the sum is 34.

The square root of 2181868 is about 1477.1147551900. The cubic root of 2181868 is about 129.7008506022.

The spelling of 2181868 in words is "two million, one hundred eighty-one thousand, eight hundred sixty-eight".