666673647 has 8 divisors (see below), whose sum is σ = 895387056. Its totient is φ = 441204672.

The previous prime is 666673643. The next prime is 666673669. The reversal of 666673647 is 746376666.

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

It is not a de Polignac number, because 666673647 - 2² = 666673643 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 666673647.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666673643) 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 7 ways as a sum of consecutive naturals, for example, 810628 + ... + 811449.

It is an arithmetic number, because the mean of its divisors is an integer number (111923382).

Almost surely, 2^666673647 is an apocalyptic number.

666673647 is a deficient number, since it is larger than the sum of its proper divisors (228713409).

666673647 is a wasteful number, since it uses less digits than its factorization.

666673647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1622217.

The product of its digits is 4572288, while the sum is 51.

The square root of 666673647 is about 25820.0241479360. The cubic root of 666673647 is about 873.5835136671.

The spelling of 666673647 in words is "six hundred sixty-six million, six hundred seventy-three thousand, six hundred forty-seven".