4001220 has 36 divisors (see below), whose sum is σ = 12137580. Its totient is φ = 1066944.

The previous prime is 4001219. The next prime is 4001227. The reversal of 4001220 is 221004.

4001220 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 2 ways, for example, as 1258884 + 2742336 = 1122^2 + 1656^2 .

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

It is a super-2 number, since 2×4001220² = 32019522976800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (4001227) 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 11 ways as a sum of consecutive naturals, for example, 10935 + ... + 11294.

It is an arithmetic number, because the mean of its divisors is an integer number (337155).

Almost surely, 2^4001220 is an apocalyptic number.

It is an amenable number.

4001220 is an abundant number, since it is smaller than the sum of its proper divisors (8136360).

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

4001220 is a wasteful number, since it uses less digits than its factorization.

4001220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22244 (or 22239 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 9.

The square root of 4001220 is about 2000.3049767473. The cubic root of 4001220 is about 158.7562421337.

Adding to 4001220 its reverse (221004), we get a palindrome (4222224).

The spelling of 4001220 in words is "four million, one thousand, two hundred twenty".