243909840 has 160 divisors (see below), whose sum is σ = 806198400. Its totient is φ = 60825600.

The previous prime is 243909793. The next prime is 243909851. The reversal of 243909840 is 48909342.

It is a congruent number.

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, 405540 + ... + 406140.

It is an arithmetic number, because the mean of its divisors is an integer number (5038740).

Almost surely, 2^243909840 is an apocalyptic number.

243909840 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 243909840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (403099200).

243909840 is an abundant number, since it is smaller than the sum of its proper divisors (562288560).

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

243909840 is a wasteful number, since it uses less digits than its factorization.

243909840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 725 (or 719 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 39.

The square root of 243909840 is about 15617.6131338947. The cubic root of 243909840 is about 624.8030013797.

The spelling of 243909840 in words is "two hundred forty-three million, nine hundred nine thousand, eight hundred forty".