420023221 has 4 divisors (see below), whose sum is σ = 421081612. Its totient is φ = 418964832.

The previous prime is 420023207. The next prime is 420023273. The reversal of 420023221 is 122320024.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 312900721 + 107122500 = 17689^2 + 10350^2 .

It is a cyclic number.

It is not a de Polignac number, because 420023221 - 2⁹ = 420022709 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 420023195 and 420023204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (420023281) 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 in 3 ways as a sum of consecutive naturals, for example, 528600 + ... + 529393.

It is an arithmetic number, because the mean of its divisors is an integer number (105270403).

Almost surely, 2^420023221 is an apocalyptic number.

It is an amenable number.

420023221 is a deficient number, since it is larger than the sum of its proper divisors (1058391).

420023221 is a wasteful number, since it uses less digits than its factorization.

420023221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1058390.

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 420023221 is about 20494.4680584786. The cubic root of 420023221 is about 748.9010399838.

Adding to 420023221 its reverse (122320024), we get a palindrome (542343245).

The spelling of 420023221 in words is "four hundred twenty million, twenty-three thousand, two hundred twenty-one".