43840013 has 4 divisors (see below), whose sum is σ = 50102880. Its totient is φ = 37577148.

The previous prime is 43839979. The next prime is 43840031. The reversal of 43840013 is 31004834.

43840013 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 43840013 - 2⁶ = 43839949 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43840033) 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, 3131423 + ... + 3131436.

It is an arithmetic number, because the mean of its divisors is an integer number (12525720).

Almost surely, 2^43840013 is an apocalyptic number.

It is an amenable number.

43840013 is a deficient number, since it is larger than the sum of its proper divisors (6262867).

43840013 is an equidigital number, since it uses as much as digits as its factorization.

43840013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6262866.

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 43840013 is about 6621.1791245971. The cubic root of 43840013 is about 352.6064276328.

Adding to 43840013 its reverse (31004834), we get a palindrome (74844847).

The spelling of 43840013 in words is "forty-three million, eight hundred forty thousand, thirteen".