243964240 has 80 divisors (see below), whose sum is σ = 631990800. Its totient is φ = 86962176.

The previous prime is 243964223. The next prime is 243964267. The reversal of 243964240 is 42469342.

It can be written as a sum of positive squares in 8 ways, for example, as 75898944 + 168065296 = 8712^2 + 12964^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is a junction number, because it is equal to n+sod(n) for n = 243964196 and 243964205.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26116 + ... + 34204.

It is an arithmetic number, because the mean of its divisors is an integer number (7899885).

Almost surely, 2^243964240 is an apocalyptic number.

243964240 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 243964240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (315995400).

243964240 is an abundant number, since it is smaller than the sum of its proper divisors (388026560).

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

243964240 is a wasteful number, since it uses less digits than its factorization.

243964240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8144 (or 8138 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 34.

The square root of 243964240 is about 15619.3546601644. The cubic root of 243964240 is about 624.8494485377.

The spelling of 243964240 in words is "two hundred forty-three million, nine hundred sixty-four thousand, two hundred forty".