43724921 has 2 divisors, whose sum is σ = 43724922. Its totient is φ = 43724920.

The previous prime is 43724917. The next prime is 43724927. The reversal of 43724921 is 12942734.

43724921 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., 43705321 + 19600 = 6611^2 + 140^2 .

It is a cyclic number.

It is not a de Polignac number, because 43724921 - 2² = 43724917 is a prime.

It is not a weakly prime, because it can be changed into another prime (43724927) 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, 21862460 + 21862461.

It is an arithmetic number, because the mean of its divisors is an integer number (21862461).

Almost surely, 2^43724921 is an apocalyptic number.

It is an amenable number.

43724921 is a deficient number, since it is larger than the sum of its proper divisors (1).

43724921 is an equidigital number, since it uses as much as digits as its factorization.

43724921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12096, while the sum is 32.

The square root of 43724921 is about 6612.4822116963. The cubic root of 43724921 is about 352.2975945131.

The spelling of 43724921 in words is "forty-three million, seven hundred twenty-four thousand, nine hundred twenty-one".