8404021 has 2 divisors, whose sum is σ = 8404022. Its totient is φ = 8404020.

The previous prime is 8404013. The next prime is 8404111. The reversal of 8404021 is 1204048.

8404021 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4363921 + 4040100 = 2089^2 + 2010^2 .

It is a cyclic number.

It is not a de Polignac number, because 8404021 - 2³ = 8404013 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 8404021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8434021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4202010 + 4202011.

It is an arithmetic number, because the mean of its divisors is an integer number (4202011).

Almost surely, 2^8404021 is an apocalyptic number.

It is an amenable number.

8404021 is a deficient number, since it is larger than the sum of its proper divisors (1).

8404021 is an equidigital number, since it uses as much as digits as its factorization.

8404021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 256, while the sum is 19.

The square root of 8404021 is about 2898.9689546458. The cubic root of 8404021 is about 203.3117021392.

Adding to 8404021 its reverse (1204048), we get a palindrome (9608069).

The spelling of 8404021 in words is "eight million, four hundred four thousand, twenty-one".