2021840 has 40 divisors (see below), whose sum is σ = 4761600. Its totient is φ = 798336.

The previous prime is 2021839. The next prime is 2021843. The reversal of 2021840 is 481202.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2021843) 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, 10061 + ... + 10259.

It is an arithmetic number, because the mean of its divisors is an integer number (119040).

2^2021840 is an apocalyptic number.

2021840 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 2021840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2380800).

2021840 is an abundant number, since it is smaller than the sum of its proper divisors (2739760).

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

2021840 is a wasteful number, since it uses less digits than its factorization.

2021840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 339 (or 333 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

The square root of 2021840 is about 1421.9142027563. The cubic root of 2021840 is about 126.4490569609.

The spelling of 2021840 in words is "two million, twenty-one thousand, eight hundred forty".