243222421 has 4 divisors (see below), whose sum is σ = 261931852. Its totient is φ = 224512992.

The previous prime is 243222407. The next prime is 243222457. The reversal of 243222421 is 124222342.

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 16719921 + 226502500 = 4089^2 + 15050^2 .

It is a cyclic number.

It is not a de Polignac number, because 243222421 - 2⁷ = 243222293 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 243222392 and 243222401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243222461) 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, 9354696 + ... + 9354721.

It is an arithmetic number, because the mean of its divisors is an integer number (65482963).

Almost surely, 2^243222421 is an apocalyptic number.

It is an amenable number.

243222421 is a deficient number, since it is larger than the sum of its proper divisors (18709431).

243222421 is a wasteful number, since it uses less digits than its factorization.

243222421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18709430.

The product of its digits is 1536, while the sum is 22.

The square root of 243222421 is about 15595.5897932717. The cubic root of 243222421 is about 624.2154815814.

Adding to 243222421 its reverse (124222342), we get a palindrome (367444763).

The spelling of 243222421 in words is "two hundred forty-three million, two hundred twenty-two thousand, four hundred twenty-one".