404220121 has 2 divisors, whose sum is σ = 404220122. Its totient is φ = 404220120.

The previous prime is 404220119. The next prime is 404220133. The reversal of 404220121 is 121022404.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 397563721 + 6656400 = 19939^2 + 2580^2 .

It is a cyclic number.

It is not a de Polignac number, because 404220121 - 2¹ = 404220119 is a prime.

Together with 404220119, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 404220095 and 404220104.

It is not a weakly prime, because it can be changed into another prime (404220161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202110060 + 202110061.

It is an arithmetic number, because the mean of its divisors is an integer number (202110061).

Almost surely, 2^404220121 is an apocalyptic number.

It is an amenable number.

404220121 is a deficient number, since it is larger than the sum of its proper divisors (1).

404220121 is an equidigital number, since it uses as much as digits as its factorization.

404220121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 404220121 is about 20105.2262111124. The cubic root of 404220121 is about 739.3884166501.

Adding to 404220121 its reverse (121022404), we get a palindrome (525242525).

The spelling of 404220121 in words is "four hundred four million, two hundred twenty thousand, one hundred twenty-one".