404512021 has 2 divisors, whose sum is σ = 404512022. Its totient is φ = 404512020.

The previous prime is 404512001. The next prime is 404512067. The reversal of 404512021 is 120215404.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 257763025 + 146748996 = 16055^2 + 12114^2 .

It is a cyclic number.

It is not a de Polignac number, because 404512021 - 2¹⁵ = 404479253 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 404512021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (404512001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202256010 + 202256011.

It is an arithmetic number, because the mean of its divisors is an integer number (202256011).

Almost surely, 2^404512021 is an apocalyptic number.

It is an amenable number.

404512021 is a deficient number, since it is larger than the sum of its proper divisors (1).

404512021 is an equidigital number, since it uses as much as digits as its factorization.

404512021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 320, while the sum is 19.

The square root of 404512021 is about 20112.4842075761. The cubic root of 404512021 is about 739.5663523313.

Adding to 404512021 its reverse (120215404), we get a palindrome (524727425).

The spelling of 404512021 in words is "four hundred four million, five hundred twelve thousand, twenty-one".