4021520 has 40 divisors (see below), whose sum is σ = 9903384. Its totient is φ = 1513472.

The previous prime is 4021519. The next prime is 4021529. The reversal of 4021520 is 251204.

4021520 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 350464 + 3671056 = 592^2 + 1916^2 .

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

It is a super-2 number, since 2×4021520² = 32345246220800, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 4021495 and 4021504.

It is not an unprimeable number, because it can be changed into a prime (4021529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 119 + ... + 2838.

Almost surely, 2^4021520 is an apocalyptic number.

4021520 is a gapful number since it is divisible by the number (40) 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 4021520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4951692).

4021520 is an abundant number, since it is smaller than the sum of its proper divisors (5881864).

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

4021520 is a wasteful number, since it uses less digits than its factorization.

4021520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2987 (or 2981 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 14.

The square root of 4021520 is about 2005.3727832999. The cubic root of 4021520 is about 159.0242701240.

Adding to 4021520 its reverse (251204), we get a palindrome (4272724).

The spelling of 4021520 in words is "four million, twenty-one thousand, five hundred twenty".