666216794 has 8 divisors (see below), whose sum is σ = 1000307028. Its totient is φ = 332781120.

The previous prime is 666216773. The next prime is 666216821. The reversal of 666216794 is 497612666.

It can be written as a sum of positive squares in 2 ways, for example, as 619362769 + 46854025 = 24887^2 + 6845^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon 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 in 3 ways as a sum of consecutive naturals, for example, 161087 + ... + 165170.

Almost surely, 2^666216794 is an apocalyptic number.

666216794 is a deficient number, since it is larger than the sum of its proper divisors (334090234).

666216794 is a wasteful number, since it uses less digits than its factorization.

666216794 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 327280.

The product of its digits is 653184, while the sum is 47.

The square root of 666216794 is about 25811.1757577992. The cubic root of 666216794 is about 873.3839205331.

The spelling of 666216794 in words is "six hundred sixty-six million, two hundred sixteen thousand, seven hundred ninety-four".