65543221 has 4 divisors (see below), whose sum is σ = 65767212. Its totient is φ = 65319232.

The previous prime is 65543213. The next prime is 65543251. The reversal of 65543221 is 12234556.

65543221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 50566321 + 14976900 = 7111^2 + 3870^2 .

It is a cyclic number.

It is not a de Polignac number, because 65543221 - 2³ = 65543213 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 65543221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65543201) 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 in 3 ways as a sum of consecutive naturals, for example, 111556 + ... + 112141.

It is an arithmetic number, because the mean of its divisors is an integer number (16441803).

Almost surely, 2^65543221 is an apocalyptic number.

It is an amenable number.

65543221 is a deficient number, since it is larger than the sum of its proper divisors (223991).

65543221 is a wasteful number, since it uses less digits than its factorization.

65543221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223990.

The product of its digits is 7200, while the sum is 28.

The square root of 65543221 is about 8095.8767900704. The cubic root of 65543221 is about 403.1895431860.

Adding to 65543221 its reverse (12234556), we get a palindrome (77777777).

The spelling of 65543221 in words is "sixty-five million, five hundred forty-three thousand, two hundred twenty-one".