666736418 has 4 divisors (see below), whose sum is σ = 1000104630. Its totient is φ = 333368208.

The previous prime is 666736349. The next prime is 666736439. The reversal of 666736418 is 814637666.

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., 643281769 + 23454649 = 25363^2 + 4843^2 .

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, 166684103 + ... + 166684106.

Almost surely, 2^666736418 is an apocalyptic number.

666736418 is a deficient number, since it is larger than the sum of its proper divisors (333368212).

666736418 is a wasteful number, since it uses less digits than its factorization.

666736418 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333368211.

The product of its digits is 870912, while the sum is 47.

The square root of 666736418 is about 25821.2396681492. The cubic root of 666736418 is about 873.6109303749.

The spelling of 666736418 in words is "six hundred sixty-six million, seven hundred thirty-six thousand, four hundred eighteen".