43030021 has 2 divisors, whose sum is σ = 43030022. Its totient is φ = 43030020.

The previous prime is 43030019. The next prime is 43030027. The reversal of 43030021 is 12003034.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 41139396 + 1890625 = 6414^2 + 1375^2 .

It is a cyclic number.

It is not a de Polignac number, because 43030021 - 2¹ = 43030019 is a prime.

Together with 43030019, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 43029983 and 43030010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43030027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21515010 + 21515011.

It is an arithmetic number, because the mean of its divisors is an integer number (21515011).

Almost surely, 2^43030021 is an apocalyptic number.

It is an amenable number.

43030021 is a deficient number, since it is larger than the sum of its proper divisors (1).

43030021 is an equidigital number, since it uses as much as digits as its factorization.

43030021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 13.

The square root of 43030021 is about 6559.7272046938. The cubic root of 43030021 is about 350.4213184775.

Adding to 43030021 its reverse (12003034), we get a palindrome (55033055).

The spelling of 43030021 in words is "forty-three million, thirty thousand, twenty-one".