666783329 has 4 divisors (see below), whose sum is σ = 666851520. Its totient is φ = 666715140.

The previous prime is 666783307. The next prime is 666783331. The reversal of 666783329 is 923387666.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 666783329 - 2¹² = 666779233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666723329) 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 in 3 ways as a sum of consecutive naturals, for example, 16349 + ... + 40010.

It is an arithmetic number, because the mean of its divisors is an integer number (166712880).

Almost surely, 2^666783329 is an apocalyptic number.

It is an amenable number.

666783329 is a deficient number, since it is larger than the sum of its proper divisors (68191).

666783329 is a wasteful number, since it uses less digits than its factorization.

666783329 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68190.

The product of its digits is 1959552, while the sum is 50.

The square root of 666783329 is about 25822.1480322610. The cubic root of 666783329 is about 873.6314187319.

It can be divided in two parts, 66678 and 3329, that added together give a palindrome (70007).

The spelling of 666783329 in words is "six hundred sixty-six million, seven hundred eighty-three thousand, three hundred twenty-nine".