2189840 has 40 divisors (see below), whose sum is σ = 5261568. Its totient is φ = 846720.

The previous prime is 2189813. The next prime is 2189843. The reversal of 2189840 is 489812.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 2189797 and 2189806.

It is not an unprimeable number, because it can be changed into a prime (2189843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2039 + ... + 2921.

2^2189840 is an apocalyptic number.

2189840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2189840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2630784).

2189840 is an abundant number, since it is smaller than the sum of its proper divisors (3071728).

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

2189840 is a wasteful number, since it uses less digits than its factorization.

2189840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 927 (or 921 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 2189840 is about 1479.8107987172. The cubic root of 2189840 is about 129.8586234273.

The spelling of 2189840 in words is "two million, one hundred eighty-nine thousand, eight hundred forty".