404666621 has 2 divisors, whose sum is σ = 404666622. Its totient is φ = 404666620.

The previous prime is 404666611. The next prime is 404666641. The reversal of 404666621 is 126666404.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 363321721 + 41344900 = 19061^2 + 6430^2 .

It is a cyclic number.

It is not a de Polignac number, because 404666621 - 2¹⁸ = 404404477 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (404666611) 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, 202333310 + 202333311.

It is an arithmetic number, because the mean of its divisors is an integer number (202333311).

Almost surely, 2^404666621 is an apocalyptic number.

It is an amenable number.

404666621 is a deficient number, since it is larger than the sum of its proper divisors (1).

404666621 is an equidigital number, since it uses as much as digits as its factorization.

404666621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 41472, while the sum is 35.

The square root of 404666621 is about 20116.3272244215. The cubic root of 404666621 is about 739.6605583451.

The spelling of 404666621 in words is "four hundred four million, six hundred sixty-six thousand, six hundred twenty-one".