4020381 has 32 divisors (see below), whose sum is σ = 6652800. Its totient is φ = 2384640.

The previous prime is 4020361. The next prime is 4020407. The reversal of 4020381 is 1830204.

It is a happy number.

It is not a de Polignac number, because 4020381 - 2⁵ = 4020349 is a prime.

It is a super-2 number, since 2×4020381² = 32326926770322, which contains 22 as substring.

It is a Curzon number.

4020381 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4020361) 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 31 ways as a sum of consecutive naturals, for example, 8491 + ... + 8951.

It is an arithmetic number, because the mean of its divisors is an integer number (207900).

Almost surely, 2^4020381 is an apocalyptic number.

It is an amenable number.

4020381 is a deficient number, since it is larger than the sum of its proper divisors (2632419).

4020381 is a wasteful number, since it uses less digits than its factorization.

4020381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 506 (or 500 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 4020381 is about 2005.0887760895. The cubic root of 4020381 is about 159.0092554242.

Adding to 4020381 its reverse (1830204), we get a palindrome (5850585).

The spelling of 4020381 in words is "four million, twenty thousand, three hundred eighty-one".