65705221 has 4 divisors (see below), whose sum is σ = 69570252. Its totient is φ = 61840192.

The previous prime is 65705203. The next prime is 65705243. The reversal of 65705221 is 12250756.

65705221 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 31024900 + 34680321 = 5570^2 + 5889^2 .

It is a cyclic number.

It is not a de Polignac number, because 65705221 - 2¹¹ = 65703173 is a prime.

It is a Duffinian number.

It is a zygodrome in base 4.

It is a self number, because there is not a number n which added to its sum of digits gives 65705221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65705261) 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, 1932490 + ... + 1932523.

It is an arithmetic number, because the mean of its divisors is an integer number (17392563).

Almost surely, 2^65705221 is an apocalyptic number.

It is an amenable number.

65705221 is a deficient number, since it is larger than the sum of its proper divisors (3865031).

65705221 is a wasteful number, since it uses less digits than its factorization.

65705221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3865030.

The product of its (nonzero) digits is 4200, while the sum is 28.

The square root of 65705221 is about 8105.8757083982. The cubic root of 65705221 is about 403.5214512278.

Adding to 65705221 its reverse (12250756), we get a palindrome (77955977).

The spelling of 65705221 in words is "sixty-five million, seven hundred five thousand, two hundred twenty-one".