66712018 has 4 divisors (see below), whose sum is σ = 100068030. Its totient is φ = 33356008.

The previous prime is 66712007. The next prime is 66712027. The reversal of 66712018 is 81021766.

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., 60326289 + 6385729 = 7767^2 + 2527^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax 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 as a sum of consecutive naturals, namely, 16678003 + ... + 16678006.

Almost surely, 2^66712018 is an apocalyptic number.

66712018 is a deficient number, since it is larger than the sum of its proper divisors (33356012).

66712018 is a wasteful number, since it uses less digits than its factorization.

66712018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33356011.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 66712018 is about 8167.7425277735. The cubic root of 66712018 is about 405.5720575203.

The spelling of 66712018 in words is "sixty-six million, seven hundred twelve thousand, eighteen".