405023221 has 2 divisors, whose sum is σ = 405023222. Its totient is φ = 405023220.

The previous prime is 405023219. The next prime is 405023237. The reversal of 405023221 is 122320504.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 310252996 + 94770225 = 17614^2 + 9735^2 .

It is a cyclic number.

It is not a de Polignac number, because 405023221 - 2¹ = 405023219 is a prime.

Together with 405023219, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (405023291) 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, 202511610 + 202511611.

It is an arithmetic number, because the mean of its divisors is an integer number (202511611).

Almost surely, 2^405023221 is an apocalyptic number.

It is an amenable number.

405023221 is a deficient number, since it is larger than the sum of its proper divisors (1).

405023221 is an equidigital number, since it uses as much as digits as its factorization.

405023221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 405023221 is about 20125.1887196120. The cubic root of 405023221 is about 739.8777622537.

Adding to 405023221 its reverse (122320504), we get a palindrome (527343725).

The spelling of 405023221 in words is "four hundred five million, twenty-three thousand, two hundred twenty-one".