66335221 has 4 divisors (see below), whose sum is σ = 66352000. Its totient is φ = 66318444.

The previous prime is 66335201. The next prime is 66335231. The reversal of 66335221 is 12253366.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66335221 - 2¹⁹ = 65810933 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66335221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66335201) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1180 + ... + 11578.

It is an arithmetic number, because the mean of its divisors is an integer number (16588000).

Almost surely, 2^66335221 is an apocalyptic number.

It is an amenable number.

66335221 is a deficient number, since it is larger than the sum of its proper divisors (16779).

66335221 is a wasteful number, since it uses less digits than its factorization.

66335221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16778.

The product of its digits is 6480, while the sum is 28.

The square root of 66335221 is about 8144.6437000031. The cubic root of 66335221 is about 404.8070431741.

Adding to 66335221 its reverse (12253366), we get a palindrome (78588587).

The spelling of 66335221 in words is "sixty-six million, three hundred thirty-five thousand, two hundred twenty-one".