243939840 has 160 divisors (see below), whose sum is σ = 814340736. Its totient is φ = 62177280.

The previous prime is 243939827. The next prime is 243939847. The reversal of 243939840 is 48939342.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (160).

It is a junction number, because it is equal to n+sod(n) for n = 243939792 and 243939801.

It is not an unprimeable number, because it can be changed into a prime (243939847) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 175950 + ... + 177330.

Almost surely, 2^243939840 is an apocalyptic number.

243939840 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 243939840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (407170368).

243939840 is an abundant number, since it is smaller than the sum of its proper divisors (570400896).

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

243939840 is a wasteful number, since it uses less digits than its factorization.

243939840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1430 (or 1414 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 42.

The square root of 243939840 is about 15618.5735584272. The cubic root of 243939840 is about 624.8286164753.

The spelling of 243939840 in words is "two hundred forty-three million, nine hundred thirty-nine thousand, eight hundred forty".