43020221 has 2 divisors, whose sum is σ = 43020222. Its totient is φ = 43020220.

The previous prime is 43020203. The next prime is 43020223. The reversal of 43020221 is 12202034.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30096196 + 12924025 = 5486^2 + 3595^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-43020221 is a prime.

Together with 43020223, 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 = 43020196 and 43020205.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43020223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21510110 + 21510111.

It is an arithmetic number, because the mean of its divisors is an integer number (21510111).

Almost surely, 2^43020221 is an apocalyptic number.

It is an amenable number.

43020221 is a deficient number, since it is larger than the sum of its proper divisors (1).

43020221 is an equidigital number, since it uses as much as digits as its factorization.

43020221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 14.

The square root of 43020221 is about 6558.9801798755. The cubic root of 43020221 is about 350.3947138762.

Adding to 43020221 its reverse (12202034), we get a palindrome (55222255).

The spelling of 43020221 in words is "forty-three million, twenty thousand, two hundred twenty-one".