66688222 has 16 divisors (see below), whose sum is σ = 102884544. Its totient is φ = 32400000.

The previous prime is 66688217. The next prime is 66688261. The reversal of 66688222 is 22288666.

It is a zygodrome in base 10.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 20722 + ... + 23722.

It is an arithmetic number, because the mean of its divisors is an integer number (6430284).

Almost surely, 2^66688222 is an apocalyptic number.

66688222 is a deficient number, since it is larger than the sum of its proper divisors (36196322).

66688222 is a wasteful number, since it uses less digits than its factorization.

66688222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3315.

The product of its digits is 110592, while the sum is 40.

The square root of 66688222 is about 8166.2856917940. The cubic root of 66688222 is about 405.5238296262.

It can be divided in two parts, 666 and 88222, that added together give a palindrome (88888).

The spelling of 66688222 in words is "sixty-six million, six hundred eighty-eight thousand, two hundred twenty-two".