66212218 has 8 divisors (see below), whose sum is σ = 102522240. Its totient is φ = 32038140.

The previous prime is 66212213. The next prime is 66212227. The reversal of 66212218 is 81221266.

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

It is not an unprimeable number, because it can be changed into a prime (66212213) 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, 533908 + ... + 534031.

It is an arithmetic number, because the mean of its divisors is an integer number (12815280).

Almost surely, 2^66212218 is an apocalyptic number.

66212218 is a deficient number, since it is larger than the sum of its proper divisors (36310022).

66212218 is a wasteful number, since it uses less digits than its factorization.

66212218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1067972.

The product of its digits is 2304, while the sum is 28.

The square root of 66212218 is about 8137.0890372418. The cubic root of 66212218 is about 404.5566820142.

It can be divided in two parts, 66212 and 218, that added together give a triangular number (66430 = T₃₆₄).

The spelling of 66212218 in words is "sixty-six million, two hundred twelve thousand, two hundred eighteen".