243155520 has 336 divisors, whose sum is σ = 898672320. Its totient is φ = 62539776.

The previous prime is 243155509. The next prime is 243155551. The reversal of 243155520 is 25551342.

It is a happy number.

243155520 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4121251 + ... + 4121309.

It is an arithmetic number, because the mean of its divisors is an integer number (2674620).

Almost surely, 2^243155520 is an apocalyptic number.

243155520 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 243155520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (449336160).

243155520 is an abundant number, since it is smaller than the sum of its proper divisors (655516800).

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

243155520 is an equidigital number, since it uses as much as digits as its factorization.

243155520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144 (or 122 counting only the distinct ones).

The product of its (nonzero) digits is 6000, while the sum is 27.

The square root of 243155520 is about 15593.4447765720. Note that the first 3 decimals coincide. The cubic root of 243155520 is about 624.1582438903.

The spelling of 243155520 in words is "two hundred forty-three million, one hundred fifty-five thousand, five hundred twenty".