666604847 has 4 divisors (see below), whose sum is σ = 668493600. Its totient is φ = 664716096.

The previous prime is 666604777. The next prime is 666604853. The reversal of 666604847 is 748406666.

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 666604847 - 2¹⁴ = 666588463 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666607847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 943847 + ... + 944552.

It is an arithmetic number, because the mean of its divisors is an integer number (167123400).

Almost surely, 2^666604847 is an apocalyptic number.

666604847 is a deficient number, since it is larger than the sum of its proper divisors (1888753).

666604847 is a wasteful number, since it uses less digits than its factorization.

666604847 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1888752.

The product of its (nonzero) digits is 1161216, while the sum is 47.

The square root of 666604847 is about 25818.6918142651. The cubic root of 666604847 is about 873.5534616751.

The spelling of 666604847 in words is "six hundred sixty-six million, six hundred four thousand, eight hundred forty-seven".