243213440 has 64 divisors (see below), whose sum is σ = 583866360. Its totient is φ = 96878592.

The previous prime is 243213409. The next prime is 243213457. The reversal of 243213440 is 44312342.

It can be written as a sum of positive squares in 4 ways, for example, as 235683904 + 7529536 = 15352^2 + 2744^2 .

It is a tau number, because it is divible by the number of its divisors (64).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 186872 + ... + 188168.

Almost surely, 2^243213440 is an apocalyptic number.

243213440 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 243213440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (291933180).

243213440 is an abundant number, since it is smaller than the sum of its proper divisors (340652920).

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

243213440 is a wasteful number, since it uses less digits than its factorization.

243213440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1609 (or 1597 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 23.

The square root of 243213440 is about 15595.3018566490. The cubic root of 243213440 is about 624.2077984242.

Adding to 243213440 its reverse (44312342), we get a palindrome (287525782).

The spelling of 243213440 in words is "two hundred forty-three million, two hundred thirteen thousand, four hundred forty".