66600666 has 48 divisors (see below), whose sum is σ = 161692128. Its totient is φ = 19634400.

The previous prime is 66600631. The next prime is 66600671.

66600666 is nontrivially palindromic in base 10.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a zygodrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 66600666.

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 23 ways as a sum of consecutive naturals, for example, 2781 + ... + 11871.

It is an arithmetic number, because the mean of its divisors is an integer number (3368586).

Almost surely, 2^66600666 is an apocalyptic number.

66600666 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 66600666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80846064).

66600666 is an abundant number, since it is smaller than the sum of its proper divisors (95091462).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66600666 is a wasteful number, since it uses less digits than its factorization.

66600666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9147 (or 9144 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 36.

The square root of 66600666 is about 8160.9231095508. The cubic root of 66600666 is about 405.3462790607.

It can be divided in two parts, 66600 and 666, that multiplied together give a square (44355600 = 6660²).

The spelling of 66600666 in words is "sixty-six million, six hundred thousand, six hundred sixty-six".