2021724 has 36 divisors (see below), whose sum is σ = 5176080. Its totient is φ = 665280.

The previous prime is 2021711. The next prime is 2021729. The reversal of 2021724 is 4271202.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a zygodrome in base 6.

It is a junction number, because it is equal to n+sod(n) for n = 2021697 and 2021706.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2021729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2889 + ... + 3519.

It is an arithmetic number, because the mean of its divisors is an integer number (143780).

2^2021724 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 2021724, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2588040).

2021724 is an abundant number, since it is smaller than the sum of its proper divisors (3154356).

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

2021724 is a wasteful number, since it uses less digits than its factorization.

2021724 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 730 (or 725 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 18.

The square root of 2021724 is about 1421.8734120870. The cubic root of 2021724 is about 126.4466386404.

Adding to 2021724 its reverse (4271202), we get a palindrome (6292926).

The spelling of 2021724 in words is "two million, twenty-one thousand, seven hundred twenty-four".