43790221 has 2 divisors, whose sum is σ = 43790222. Its totient is φ = 43790220.

The previous prime is 43790207. The next prime is 43790237. The reversal of 43790221 is 12209734.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 41860900 + 1929321 = 6470^2 + 1389^2 .

It is a cyclic number.

It is not a de Polignac number, because 43790221 - 2⁹ = 43789709 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 43790221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43790251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21895110 + 21895111.

It is an arithmetic number, because the mean of its divisors is an integer number (21895111).

Almost surely, 2^43790221 is an apocalyptic number.

It is an amenable number.

43790221 is a deficient number, since it is larger than the sum of its proper divisors (1).

43790221 is an equidigital number, since it uses as much as digits as its factorization.

43790221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3024, while the sum is 28.

The square root of 43790221 is about 6617.4180010031. The cubic root of 43790221 is about 352.4728842546.

Adding to 43790221 its reverse (12209734), we get a palindrome (55999955).

The spelling of 43790221 in words is "forty-three million, seven hundred ninety thousand, two hundred twenty-one".