666819323 has 4 divisors (see below), whose sum is σ = 667286088. Its totient is φ = 666352560.

The previous prime is 666819311. The next prime is 666819343. The reversal of 666819323 is 323918666.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 666819323 - 2¹⁸ = 666557179 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666819343) 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, 231233 + ... + 234098.

It is an arithmetic number, because the mean of its divisors is an integer number (166821522).

Almost surely, 2^666819323 is an apocalyptic number.

666819323 is a deficient number, since it is larger than the sum of its proper divisors (466765).

666819323 is a wasteful number, since it uses less digits than its factorization.

666819323 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 466764.

The product of its digits is 279936, while the sum is 44.

The square root of 666819323 is about 25822.8449826893. The cubic root of 666819323 is about 873.6471384428.

The spelling of 666819323 in words is "six hundred sixty-six million, eight hundred nineteen thousand, three hundred twenty-three".