243121243220 has 24 divisors (see below), whose sum is σ = 523007164008. Its totient is φ = 94876582400.

The previous prime is 243121243213. The next prime is 243121243229. The reversal of 243121243220 is 22342121342.

It can be written as a sum of positive squares in 4 ways, for example, as 1609935376 + 241511307844 = 40124^2 + 491438^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 243121243220.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243121243229) 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, 148243841 + ... + 148245480.

It is an arithmetic number, because the mean of its divisors is an integer number (21791965167).

Almost surely, 2^243121243220 is an apocalyptic number.

243121243220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

243121243220 is an abundant number, since it is smaller than the sum of its proper divisors (279885920788).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

243121243220 is a wasteful number, since it uses less digits than its factorization.

243121243220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 296489371 (or 296489369 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 26.

Adding to 243121243220 its reverse (22342121342), we get a palindrome (265463364562).

The spelling of 243121243220 in words is "two hundred forty-three billion, one hundred twenty-one million, two hundred forty-three thousand, two hundred twenty".