65630221 has 2 divisors, whose sum is σ = 65630222. Its totient is φ = 65630220.

The previous prime is 65630209. The next prime is 65630233. The reversal of 65630221 is 12203656.

65630221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a balanced prime because it is at equal distance from previous prime (65630209) and next prime (65630233).

It can be written as a sum of positive squares in only one way, i.e., 37380996 + 28249225 = 6114^2 + 5315^2 .

It is a cyclic number.

It is not a de Polignac number, because 65630221 - 2⁷ = 65630093 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (65630281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32815110 + 32815111.

It is an arithmetic number, because the mean of its divisors is an integer number (32815111).

Almost surely, 2^65630221 is an apocalyptic number.

It is an amenable number.

65630221 is a deficient number, since it is larger than the sum of its proper divisors (1).

65630221 is an equidigital number, since it uses as much as digits as its factorization.

65630221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 65630221 is about 8101.2481137168. The cubic root of 65630221 is about 403.3678579983.

Adding to 65630221 its reverse (12203656), we get a palindrome (77833877).

The spelling of 65630221 in words is "sixty-five million, six hundred thirty thousand, two hundred twenty-one".