4021820 has 48 divisors (see below), whose sum is σ = 9356256. Its totient is φ = 1440000.

The previous prime is 4021777. The next prime is 4021867. The reversal of 4021820 is 281204.

It is a super-2 number, since 2×4021820² = 32350072224800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22130 + ... + 22310.

It is an arithmetic number, because the mean of its divisors is an integer number (194922).

Almost surely, 2^4021820 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 4021820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4678128).

4021820 is an abundant number, since it is smaller than the sum of its proper divisors (5334436).

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

4021820 is a wasteful number, since it uses less digits than its factorization.

4021820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 302 (or 300 counting only the distinct ones).

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

The square root of 4021820 is about 2005.4475809654. The cubic root of 4021820 is about 159.0282243581.

It can be divided in two parts, 402 and 1820, that added together give a palindrome (2222).

The spelling of 4021820 in words is "four million, twenty-one thousand, eight hundred twenty".