243305640 has 256 divisors, whose sum is σ = 870912000. Its totient is φ = 60238080.

The previous prime is 243305633. The next prime is 243305663. The reversal of 243305640 is 46503342.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1456837 + ... + 1457003.

It is an arithmetic number, because the mean of its divisors is an integer number (3402000).

Almost surely, 2^243305640 is an apocalyptic number.

243305640 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 243305640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (435456000).

243305640 is an abundant number, since it is smaller than the sum of its proper divisors (627606360).

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

243305640 is a wasteful number, since it uses less digits than its factorization.

243305640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 277 (or 267 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 27.

The square root of 243305640 is about 15598.2575950008. The cubic root of 243305640 is about 624.2866656229.

Adding to 243305640 its reverse (46503342), we get a palindrome (289808982).

The spelling of 243305640 in words is "two hundred forty-three million, three hundred five thousand, six hundred forty".