66412221 has 8 divisors (see below), whose sum is σ = 88616160. Its totient is φ = 44241552.

The previous prime is 66412207. The next prime is 66412243. The reversal of 66412221 is 12221466.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 66412221 - 2⁵ = 66412189 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 66412191 and 66412200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66412321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3210 + ... + 11963.

It is an arithmetic number, because the mean of its divisors is an integer number (11077020).

Almost surely, 2^66412221 is an apocalyptic number.

It is an amenable number.

66412221 is a deficient number, since it is larger than the sum of its proper divisors (22203939).

66412221 is a wasteful number, since it uses less digits than its factorization.

66412221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16635.

The product of its digits is 1152, while the sum is 24.

The square root of 66412221 is about 8149.3693621040. The cubic root of 66412221 is about 404.9636120333.

Adding to 66412221 its reverse (12221466), we get a palindrome (78633687).

The spelling of 66412221 in words is "sixty-six million, four hundred twelve thousand, two hundred twenty-one".