243121522213 has 4 divisors (see below), whose sum is σ = 245393686080. Its totient is φ = 240849358348.

The previous prime is 243121522211. The next prime is 243121522271. The reversal of 243121522213 is 312225121342.

It is a happy number.

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 243121522213 - 2¹ = 243121522211 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243121522211) 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, 1136081773 + ... + 1136081986.

It is an arithmetic number, because the mean of its divisors is an integer number (61348421520).

Almost surely, 2^243121522213 is an apocalyptic number.

It is an amenable number.

243121522213 is a deficient number, since it is larger than the sum of its proper divisors (2272163867).

243121522213 is a wasteful number, since it uses less digits than its factorization.

243121522213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2272163866.

The product of its digits is 5760, while the sum is 28.

Adding to 243121522213 its reverse (312225121342), we get a palindrome (555346643555).

The spelling of 243121522213 in words is "two hundred forty-three billion, one hundred twenty-one million, five hundred twenty-two thousand, two hundred thirteen".