66763666 has 4 divisors (see below), whose sum is σ = 100145502. Its totient is φ = 33381832.

The previous prime is 66763661. The next prime is 66763679. The reversal of 66763666 is 66636766.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 62015625 + 4748041 = 7875^2 + 2179^2 .

It is not an unprimeable number, because it can be changed into a prime (66763661) 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 as a sum of consecutive naturals, namely, 16690915 + ... + 16690918.

Almost surely, 2^66763666 is an apocalyptic number.

66763666 is a deficient number, since it is larger than the sum of its proper divisors (33381836).

66763666 is a wasteful number, since it uses less digits than its factorization.

66763666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33381835.

The product of its digits is 979776, while the sum is 46.

The square root of 66763666 is about 8170.9036219992. The cubic root of 66763666 is about 405.6766942504.

The spelling of 66763666 in words is "sixty-six million, seven hundred sixty-three thousand, six hundred sixty-six".