43640240 has 40 divisors (see below), whose sum is σ = 115959840. Its totient is φ = 14962176.

The previous prime is 43640239. The next prime is 43640243. The reversal of 43640240 is 4204634.

It is a happy number.

43640240 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (43640243) 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 7 ways as a sum of consecutive naturals, for example, 38405 + ... + 39524.

It is an arithmetic number, because the mean of its divisors is an integer number (2898996).

Almost surely, 2^43640240 is an apocalyptic number.

43640240 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

43640240 is an abundant number, since it is smaller than the sum of its proper divisors (72319600).

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

43640240 is a wasteful number, since it uses less digits than its factorization.

43640240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77949 (or 77943 counting only the distinct ones).

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

The square root of 43640240 is about 6606.0759910858. The cubic root of 43640240 is about 352.0700187846.

Adding to 43640240 its reverse (4204634), we get a palindrome (47844874).

The spelling of 43640240 in words is "forty-three million, six hundred forty thousand, two hundred forty".