43989521 has 2 divisors, whose sum is σ = 43989522. Its totient is φ = 43989520.

The previous prime is 43989511. The next prime is 43989551. The reversal of 43989521 is 12598934.

43989521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 40132225 + 3857296 = 6335^2 + 1964^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-43989521 is a prime.

It is not a weakly prime, because it can be changed into another prime (43989511) 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 as a sum of consecutive naturals, namely, 21994760 + 21994761.

It is an arithmetic number, because the mean of its divisors is an integer number (21994761).

Almost surely, 2^43989521 is an apocalyptic number.

It is an amenable number.

43989521 is a deficient number, since it is larger than the sum of its proper divisors (1).

43989521 is an equidigital number, since it uses as much as digits as its factorization.

43989521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 77760, while the sum is 41.

The square root of 43989521 is about 6632.4596493307. The cubic root of 43989521 is about 353.0068051557.

The spelling of 43989521 in words is "forty-three million, nine hundred eighty-nine thousand, five hundred twenty-one".