66189778 has 8 divisors (see below), whose sum is σ = 99498672. Its totient is φ = 33023556.

The previous prime is 66189751. The next prime is 66189779. The reversal of 66189778 is 87798166.

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 (66189779) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 34500 + ... + 36367.

It is an arithmetic number, because the mean of its divisors is an integer number (12437334).

Almost surely, 2^66189778 is an apocalyptic number.

66189778 is a deficient number, since it is larger than the sum of its proper divisors (33308894).

66189778 is a wasteful number, since it uses less digits than its factorization.

66189778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71336.

The product of its digits is 1016064, while the sum is 52.

The square root of 66189778 is about 8135.7100489140. The cubic root of 66189778 is about 404.5109740468.

The spelling of 66189778 in words is "sixty-six million, one hundred eighty-nine thousand, seven hundred seventy-eight".