65506221 has 12 divisors (see below), whose sum is σ = 103222080. Its totient is φ = 39700680.

The previous prime is 65506201. The next prime is 65506229. The reversal of 65506221 is 12260556.

65506221 is a `hidden beast` number, since 655 + 0 + 6 + 2 + 2 + 1 = 666.

It is not a de Polignac number, because 65506221 - 2¹⁹ = 64981933 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65506229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 330741 + ... + 330938.

It is an arithmetic number, because the mean of its divisors is an integer number (8601840).

Almost surely, 2^65506221 is an apocalyptic number.

It is an amenable number.

65506221 is a deficient number, since it is larger than the sum of its proper divisors (37715859).

65506221 is a wasteful number, since it uses less digits than its factorization.

65506221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 661696 (or 661693 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 65506221 is about 8093.5913536575. The cubic root of 65506221 is about 403.1136603264.

Adding to 65506221 its reverse (12260556), we get a palindrome (77766777).

The spelling of 65506221 in words is "sixty-five million, five hundred six thousand, two hundred twenty-one".