400004044421 has 2 divisors, whose sum is σ = 400004044422. Its totient is φ = 400004044420.

The previous prime is 400004044397. The next prime is 400004044423. The reversal of 400004044421 is 124440400004.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 256998302500 + 143005741921 = 506950^2 + 378161^2 .

It is a cyclic number.

It is not a de Polignac number, because 400004044421 - 2⁶ = 400004044357 is a prime.

Together with 400004044423, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400004044423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200002022210 + 200002022211.

It is an arithmetic number, because the mean of its divisors is an integer number (200002022211).

Almost surely, 2^400004044421 is an apocalyptic number.

It is an amenable number.

400004044421 is a deficient number, since it is larger than the sum of its proper divisors (1).

400004044421 is an equidigital number, since it uses as much as digits as its factorization.

400004044421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2048, while the sum is 23.

Adding to 400004044421 its reverse (124440400004), we get a palindrome (524444444425).

The spelling of 400004044421 in words is "four hundred billion, four million, forty-four thousand, four hundred twenty-one".