243121213221 has 8 divisors (see below), whose sum is σ = 324935274720. Its totient is φ = 161693980272.

The previous prime is 243121213189. The next prime is 243121213333. The reversal of 243121213221 is 122312121342.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 243121213221 - 2⁵ = 243121213189 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 243121213191 and 243121213200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243121213021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 96705670 + ... + 96708183.

It is an arithmetic number, because the mean of its divisors is an integer number (40616909340).

Almost surely, 2^243121213221 is an apocalyptic number.

It is an amenable number.

243121213221 is a deficient number, since it is larger than the sum of its proper divisors (81814061499).

243121213221 is a wasteful number, since it uses less digits than its factorization.

243121213221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193414275.

The product of its digits is 1152, while the sum is 24.

Adding to 243121213221 its reverse (122312121342), we get a palindrome (365433334563).

The spelling of 243121213221 in words is "two hundred forty-three billion, one hundred twenty-one million, two hundred thirteen thousand, two hundred twenty-one".