4002021 has 16 divisors (see below), whose sum is σ = 6278400. Its totient is φ = 2510784.

The previous prime is 4002017. The next prime is 4002041. The reversal of 4002021 is 1202004.

4002021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 4002021 - 2² = 4002017 is a prime.

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

It is a junction number, because it is equal to n+sod(n) for n = 4001994 and 4002012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4002001) 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 15 ways as a sum of consecutive naturals, for example, 3901 + ... + 4818.

It is an arithmetic number, because the mean of its divisors is an integer number (392400).

Almost surely, 2^4002021 is an apocalyptic number.

It is an amenable number.

4002021 is a deficient number, since it is larger than the sum of its proper divisors (2276379).

4002021 is a wasteful number, since it uses less digits than its factorization.

4002021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8745 (or 8739 counting only the distinct ones).

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

The square root of 4002021 is about 2000.5051861967. The cubic root of 4002021 is about 158.7668351749.

Adding to 4002021 its reverse (1202004), we get a palindrome (5204025).

The spelling of 4002021 in words is "four million, two thousand, twenty-one".