243121340000 has 720 divisors, whose sum is σ = 799639283520. Its totient is φ = 71729280000.

The previous prime is 243121339991. The next prime is 243121340003. The reversal of 243121340000 is 43121342.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243121340003) by changing a digit.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 204819407 + ... + 204820593.

It is an arithmetic number, because the mean of its divisors is an integer number (1110610116).

Almost surely, 2^243121340000 is an apocalyptic number.

243121340000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 243121340000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (399819641760).

243121340000 is an abundant number, since it is smaller than the sum of its proper divisors (556517943520).

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

243121340000 is a wasteful number, since it uses less digits than its factorization.

243121340000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1261 (or 1231 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 243121340000 its reverse (43121342), we get a palindrome (243164461342).

The spelling of 243121340000 in words is "two hundred forty-three billion, one hundred twenty-one million, three hundred forty thousand".