4400004004021 has 2 divisors, whose sum is σ = 4400004004022. Its totient is φ = 4400004004020.

The previous prime is 4400004003977. The next prime is 4400004004057. The reversal of 4400004004021 is 1204004000044.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3941173887121 + 458830116900 = 1985239^2 + 677370^2 .

It is a cyclic number.

It is not a de Polignac number, because 4400004004021 - 2³⁹ = 3850248190133 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 4400004004021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4400004004061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2200002002010 + 2200002002011.

It is an arithmetic number, because the mean of its divisors is an integer number (2200002002011).

Almost surely, 2^{4400004004021} is an apocalyptic number.

It is an amenable number.

4400004004021 is a deficient number, since it is larger than the sum of its proper divisors (1).

4400004004021 is an equidigital number, since it uses as much as digits as its factorization.

4400004004021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 512, while the sum is 19.

Adding to 4400004004021 its reverse (1204004000044), we get a palindrome (5604008004065).

The spelling of 4400004004021 in words is "four trillion, four hundred billion, four million, four thousand, twenty-one".