43218640 has 20 divisors (see below), whose sum is σ = 100483524. Its totient is φ = 17287424.

The previous prime is 43218631. The next prime is 43218647. The reversal of 43218640 is 4681234.

43218640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 10316944 + 32901696 = 3212^2 + 5736^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 43218599 and 43218608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43218647) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 270037 + ... + 270196.

Almost surely, 2^43218640 is an apocalyptic number.

43218640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

43218640 is an abundant number, since it is smaller than the sum of its proper divisors (57264884).

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

43218640 is a wasteful number, since it uses less digits than its factorization.

43218640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 540246 (or 540240 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 28.

The square root of 43218640 is about 6574.0885299789. The cubic root of 43218640 is about 350.9325877091.

Adding to 43218640 its reverse (4681234), we get a palindrome (47899874).

The spelling of 43218640 in words is "forty-three million, two hundred eighteen thousand, six hundred forty".