404423021 has 2 divisors, whose sum is σ = 404423022. Its totient is φ = 404423020.

The previous prime is 404423017. The next prime is 404423059. The reversal of 404423021 is 120324404.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 395452996 + 8970025 = 19886^2 + 2995^2 .

It is a cyclic number.

It is not a de Polignac number, because 404423021 - 2² = 404423017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 404422984 and 404423002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (404423321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202211510 + 202211511.

It is an arithmetic number, because the mean of its divisors is an integer number (202211511).

Almost surely, 2^404423021 is an apocalyptic number.

It is an amenable number.

404423021 is a deficient number, since it is larger than the sum of its proper divisors (1).

404423021 is an equidigital number, since it uses as much as digits as its factorization.

404423021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 768, while the sum is 20.

The square root of 404423021 is about 20110.2715297432. The cubic root of 404423021 is about 739.5121090045.

Adding to 404423021 its reverse (120324404), we get a palindrome (524747425).

The spelling of 404423021 in words is "four hundred four million, four hundred twenty-three thousand, twenty-one".