2161684 has 36 divisors (see below), whose sum is σ = 4524660. Its totient is φ = 900480.

The previous prime is 2161639. The next prime is 2161697. The reversal of 2161684 is 4861612.

It can be written as a sum of positive squares in 2 ways, for example, as 122500 + 2039184 = 350^2 + 1428^2 .

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7902 + ... + 8170.

It is an arithmetic number, because the mean of its divisors is an integer number (125685).

2^2161684 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2161684, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2262330).

2161684 is an abundant number, since it is smaller than the sum of its proper divisors (2362976).

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

2161684 is a wasteful number, since it uses less digits than its factorization.

2161684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 328 (or 319 counting only the distinct ones).

The product of its digits is 2304, while the sum is 28.

The square root of 2161684 is about 1470.2666424836. The cubic root of 2161684 is about 129.2996658980.

The spelling of 2161684 in words is "two million, one hundred sixty-one thousand, six hundred eighty-four".