4381021 has 4 divisors (see below), whose sum is σ = 4385952. Its totient is φ = 4376092.

The previous prime is 4381009. The next prime is 4381031. The reversal of 4381021 is 1201834.

It is the 855-th star number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 4381021 - 2¹⁹ = 3856733 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 4381021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4381031) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 721 + ... + 3046.

It is an arithmetic number, because the mean of its divisors is an integer number (1096488).

Almost surely, 2^4381021 is an apocalyptic number.

It is an amenable number.

4381021 is a deficient number, since it is larger than the sum of its proper divisors (4931).

4381021 is a wasteful number, since it uses less digits than its factorization.

4381021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4930.

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 4381021 is about 2093.0888657675. The cubic root of 4381021 is about 163.6283100320.

Adding to 4381021 its reverse (1201834), we get a palindrome (5582855).

The spelling of 4381021 in words is "four million, three hundred eighty-one thousand, twenty-one".