243121112520 has 128 divisors (see below), whose sum is σ = 856874471040. Its totient is φ = 54404720640.

The previous prime is 243121112431. The next prime is 243121112537. The reversal of 243121112520 is 25211121342.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7066789 + ... + 7101108.

It is an arithmetic number, because the mean of its divisors is an integer number (6694331805).

Almost surely, 2^243121112520 is an apocalyptic number.

243121112520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

243121112520 is an abundant number, since it is smaller than the sum of its proper divisors (613753358520).

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

243121112520 is a wasteful number, since it uses less digits than its factorization.

243121112520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14167935 (or 14167931 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 24.

Adding to 243121112520 its reverse (25211121342), we get a palindrome (268332233862).

The spelling of 243121112520 in words is "two hundred forty-three billion, one hundred twenty-one million, one hundred twelve thousand, five hundred twenty".