2121868 has 12 divisors (see below), whose sum is σ = 4243792. Its totient is φ = 909360.

The previous prime is 2121853. The next prime is 2121869. The reversal of 2121868 is 8681212.

2121868 is an admirable number.

It is a Harshad number since it is a multiple of its sum of digits (28), and also a Moran number because the ratio is a prime number: 75781 = 2121868 / (2 + 1 + 2 + 1 + 8 + 6 + 8).

It is not an unprimeable number, because it can be changed into a prime (2121869) 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, 37863 + ... + 37918.

2^2121868 is an apocalyptic number.

2121868 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

2121868 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

2121868 is a wasteful number, since it uses less digits than its factorization.

2121868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75792 (or 75790 counting only the distinct ones).

The product of its digits is 1536, while the sum is 28.

The square root of 2121868 is about 1456.6633104462. The cubic root of 2121868 is about 128.5008857000.

It can be divided in two parts, 212 and 1868, that added together give a triangular number (2080 = T₆₄).

The spelling of 2121868 in words is "two million, one hundred twenty-one thousand, eight hundred sixty-eight".