66366221 has 4 divisors (see below), whose sum is σ = 69859200. Its totient is φ = 62873244.

The previous prime is 66366217. The next prime is 66366269. The reversal of 66366221 is 12266366.

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 66366221 - 2² = 66366217 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66366211) 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, 1746461 + ... + 1746498.

It is an arithmetic number, because the mean of its divisors is an integer number (17464800).

Almost surely, 2^66366221 is an apocalyptic number.

It is an amenable number.

66366221 is a deficient number, since it is larger than the sum of its proper divisors (3492979).

66366221 is a wasteful number, since it uses less digits than its factorization.

66366221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3492978.

The product of its digits is 15552, while the sum is 32.

The square root of 66366221 is about 8146.5465689456. The cubic root of 66366221 is about 404.8700919529.

The spelling of 66366221 in words is "sixty-six million, three hundred sixty-six thousand, two hundred twenty-one".