423502021 has 2 divisors, whose sum is σ = 423502022. Its totient is φ = 423502020.

The previous prime is 423501979. The next prime is 423502031. The reversal of 423502021 is 120205324.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 423330625 + 171396 = 20575^2 + 414^2 .

It is a cyclic number.

It is not a de Polignac number, because 423502021 - 2¹⁵ = 423469253 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 423502021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (423502031) 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, 211751010 + 211751011.

It is an arithmetic number, because the mean of its divisors is an integer number (211751011).

Almost surely, 2^423502021 is an apocalyptic number.

It is an amenable number.

423502021 is a deficient number, since it is larger than the sum of its proper divisors (1).

423502021 is an equidigital number, since it uses as much as digits as its factorization.

423502021 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 423502021 is about 20579.1647303772. The cubic root of 423502021 is about 750.9629237673.

Adding to 423502021 its reverse (120205324), we get a palindrome (543707345).

The spelling of 423502021 in words is "four hundred twenty-three million, five hundred two thousand, twenty-one".