666783818 has 8 divisors (see below), whose sum is σ = 1003010148. Its totient is φ = 332447104.

The previous prime is 666783811. The next prime is 666783827. The reversal of 666783818 is 818387666.

666783818 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 612216049 + 54567769 = 24743^2 + 7387^2 .

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

It is a self number, because there is not a number n which added to its sum of digits gives 666783818.

It is not an unprimeable number, because it can be changed into a prime (666783811) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 471521 + ... + 472932.

Almost surely, 2^666783818 is an apocalyptic number.

666783818 is a deficient number, since it is larger than the sum of its proper divisors (336226330).

666783818 is a wasteful number, since it uses less digits than its factorization.

666783818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 944808.

The product of its digits is 2322432, while the sum is 53.

The square root of 666783818 is about 25822.1575008751. The cubic root of 666783818 is about 873.6316322974.

The spelling of 666783818 in words is "six hundred sixty-six million, seven hundred eighty-three thousand, eight hundred eighteen".