43430021 has 4 divisors (see below), whose sum is σ = 44354112. Its totient is φ = 42505932.

The previous prime is 43430017. The next prime is 43430027. The reversal of 43430021 is 12003434.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12003434 = 2 ⋅6001717.

It is a cyclic number.

It is not a de Polignac number, because 43430021 - 2² = 43430017 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 (43430027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 461975 + ... + 462068.

It is an arithmetic number, because the mean of its divisors is an integer number (11088528).

Almost surely, 2^43430021 is an apocalyptic number.

It is an amenable number.

43430021 is a deficient number, since it is larger than the sum of its proper divisors (924091).

43430021 is an equidigital number, since it uses as much as digits as its factorization.

43430021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 924090.

The product of its (nonzero) digits is 288, while the sum is 17.

The square root of 43430021 is about 6590.1457495263. The cubic root of 43430021 is about 351.5037908654.

Adding to 43430021 its reverse (12003434), we get a palindrome (55433455).

The spelling of 43430021 in words is "forty-three million, four hundred thirty thousand, twenty-one".