2121684 has 12 divisors (see below), whose sum is σ = 4950624. Its totient is φ = 707224.

The previous prime is 2121683. The next prime is 2121737. The reversal of 2121684 is 4861212.

2121684 is digitally balanced in base 2 and base 5, because in such bases it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 88392 + ... + 88415.

It is an arithmetic number, because the mean of its divisors is an integer number (412552).

2^2121684 is an apocalyptic number.

It is an amenable number.

2121684 is an abundant number, since it is smaller than the sum of its proper divisors (2828940).

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

2121684 is a wasteful number, since it uses less digits than its factorization.

2121684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 176814 (or 176812 counting only the distinct ones).

The product of its digits is 768, while the sum is 24.

The square root of 2121684 is about 1456.6001510367. The cubic root of 2121684 is about 128.4971712297.

Adding to 2121684 its reverse (4861212), we get a palindrome (6982896).

The spelling of 2121684 in words is "two million, one hundred twenty-one thousand, six hundred eighty-four".