66633666 has 16 divisors (see below), whose sum is σ = 145382688. Its totient is φ = 20192000.

The previous prime is 66633661. The next prime is 66633689.

66633666 is nontrivially palindromic in base 10.

It is a nude number because it is divisible by every one of its digits.

It is a zygodrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (66633661) 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 7 ways as a sum of consecutive naturals, for example, 504735 + ... + 504866.

It is an arithmetic number, because the mean of its divisors is an integer number (9086418).

Almost surely, 2^66633666 is an apocalyptic number.

66633666 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

66633666 is an abundant number, since it is smaller than the sum of its proper divisors (78749022).

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

66633666 is a wasteful number, since it uses less digits than its factorization.

66633666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1009617.

The product of its digits is 419904, while the sum is 42.

The square root of 66633666 is about 8162.9446892650. The cubic root of 66633666 is about 405.4132164220.

It can be divided in two parts, 666 and 33666, that multiplied together give a triangular number (22421556 = T₆₆₉₆).

The spelling of 66633666 in words is "sixty-six million, six hundred thirty-three thousand, six hundred sixty-six".