43423021 has 4 divisors (see below), whose sum is σ = 43436700. Its totient is φ = 43409344.

The previous prime is 43423019. The next prime is 43423043. The reversal of 43423021 is 12032434.

43423021 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 brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 19900521 + 23522500 = 4461^2 + 4850^2 .

It is a cyclic number.

It is not a de Polignac number, because 43423021 - 2¹ = 43423019 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 43423021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43423921) 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, 675 + ... + 9343.

It is an arithmetic number, because the mean of its divisors is an integer number (10859175).

Almost surely, 2^43423021 is an apocalyptic number.

It is an amenable number.

43423021 is a deficient number, since it is larger than the sum of its proper divisors (13679).

43423021 is an equidigital number, since it uses as much as digits as its factorization.

43423021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13678.

The product of its (nonzero) digits is 576, while the sum is 19.

The square root of 43423021 is about 6589.6146321314. The cubic root of 43423021 is about 351.4849048607.

Adding to 43423021 its reverse (12032434), we get a palindrome (55455455).

The spelling of 43423021 in words is "forty-three million, four hundred twenty-three thousand, twenty-one".