43450021 has 2 divisors, whose sum is σ = 43450022. Its totient is φ = 43450020.

The previous prime is 43450009. The next prime is 43450027. The reversal of 43450021 is 12005434.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 41796225 + 1653796 = 6465^2 + 1286^2 .

It is a cyclic number.

It is not a de Polignac number, because 43450021 - 2⁹ = 43449509 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43450027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21725010 + 21725011.

It is an arithmetic number, because the mean of its divisors is an integer number (21725011).

Almost surely, 2^43450021 is an apocalyptic number.

It is an amenable number.

43450021 is a deficient number, since it is larger than the sum of its proper divisors (1).

43450021 is an equidigital number, since it uses as much as digits as its factorization.

43450021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 43450021 is about 6591.6629919922. The cubic root of 43450021 is about 351.5577396992.

Adding to 43450021 its reverse (12005434), we get a palindrome (55455455).

The spelling of 43450021 in words is "forty-three million, four hundred fifty thousand, twenty-one".