4401821 has 4 divisors (see below), whose sum is σ = 4474044. Its totient is φ = 4329600.

The previous prime is 4401811. The next prime is 4401829. The reversal of 4401821 is 1281044.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1876900 + 2524921 = 1370^2 + 1589^2 .

It is a cyclic number.

It is not a de Polignac number, because 4401821 - 2¹⁸ = 4139677 is a prime.

It is a super-3 number, since 3×4401821³ (a number of 21 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 4401793 and 4401802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4401829) 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 3 ways as a sum of consecutive naturals, for example, 36020 + ... + 36141.

It is an arithmetic number, because the mean of its divisors is an integer number (1118511).

Almost surely, 2^4401821 is an apocalyptic number.

It is an amenable number.

4401821 is a deficient number, since it is larger than the sum of its proper divisors (72223).

4401821 is an equidigital number, since it uses as much as digits as its factorization.

4401821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72222.

The product of its (nonzero) digits is 256, while the sum is 20.

The square root of 4401821 is about 2098.0517152825. The cubic root of 4401821 is about 163.8868568210.

Adding to 4401821 its reverse (1281044), we get a palindrome (5682865).

The spelling of 4401821 in words is "four million, four hundred one thousand, eight hundred twenty-one".