2185640 has 32 divisors (see below), whose sum is σ = 4975560. Its totient is φ = 864000.

The previous prime is 2185637. The next prime is 2185649. The reversal of 2185640 is 465812.

It can be written as a sum of positive squares in 4 ways, for example, as 2079364 + 106276 = 1442^2 + 326^2 .

It is not an unprimeable number, because it can be changed into a prime (2185649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3770 + ... + 4310.

2^2185640 is an apocalyptic number.

2185640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2185640 is an abundant number, since it is smaller than the sum of its proper divisors (2789920).

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

2185640 is a wasteful number, since it uses less digits than its factorization.

2185640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 653 (or 649 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 26.

The square root of 2185640 is about 1478.3910172887. The cubic root of 2185640 is about 129.7755495837.

The spelling of 2185640 in words is "two million, one hundred eighty-five thousand, six hundred forty".