420221221 has 4 divisors (see below), whose sum is σ = 480252832. Its totient is φ = 360189612.

The previous prime is 420221203. The next prime is 420221231. The reversal of 420221221 is 122122024.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 420221221 - 2²⁷ = 286003493 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 420221195 and 420221204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (420221231) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30015795 + ... + 30015808.

It is an arithmetic number, because the mean of its divisors is an integer number (120063208).

Almost surely, 2^420221221 is an apocalyptic number.

It is an amenable number.

420221221 is a deficient number, since it is larger than the sum of its proper divisors (60031611).

420221221 is an equidigital number, since it uses as much as digits as its factorization.

420221221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60031610.

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

The square root of 420221221 is about 20499.2980611532. The cubic root of 420221221 is about 749.0186994404.

Adding to 420221221 its reverse (122122024), we get a palindrome (542343245).

The spelling of 420221221 in words is "four hundred twenty million, two hundred twenty-one thousand, two hundred twenty-one".