43501721 has 4 divisors (see below), whose sum is σ = 43742244. Its totient is φ = 43261200.

The previous prime is 43501709. The next prime is 43501727. The reversal of 43501721 is 12710534.

43501721 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.

It can be written as a sum of positive squares in 2 ways, for example, as 8265625 + 35236096 = 2875^2 + 5936^2 .

It is a cyclic number.

It is not a de Polignac number, because 43501721 - 2¹⁰ = 43500697 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (43501727) 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, 119990 + ... + 120351.

It is an arithmetic number, because the mean of its divisors is an integer number (10935561).

Almost surely, 2^43501721 is an apocalyptic number.

It is an amenable number.

43501721 is a deficient number, since it is larger than the sum of its proper divisors (240523).

43501721 is a wasteful number, since it uses less digits than its factorization.

43501721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240522.

The product of its (nonzero) digits is 840, while the sum is 23.

The square root of 43501721 is about 6595.5834465193. The cubic root of 43501721 is about 351.6971207676.

The spelling of 43501721 in words is "forty-three million, five hundred one thousand, seven hundred twenty-one".