421202221 has 4 divisors (see below), whose sum is σ = 459493344. Its totient is φ = 382911100.

The previous prime is 421202213. The next prime is 421202237. The reversal of 421202221 is 122202124.

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 not a de Polignac number, because 421202221 - 2³ = 421202213 is a prime.

It is a super-2 number, since 2×421202221² = 354822621950665682, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 421202195 and 421202204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421202281) 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, 19145545 + ... + 19145566.

It is an arithmetic number, because the mean of its divisors is an integer number (114873336).

Almost surely, 2^421202221 is an apocalyptic number.

It is an amenable number.

421202221 is a deficient number, since it is larger than the sum of its proper divisors (38291123).

421202221 is a wasteful number, since it uses less digits than its factorization.

421202221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38291122.

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

The square root of 421202221 is about 20523.2117613204. The cubic root of 421202221 is about 749.6011040284.

Adding to 421202221 its reverse (122202124), we get a palindrome (543404345).

The spelling of 421202221 in words is "four hundred twenty-one million, two hundred two thousand, two hundred twenty-one".