669647 has 8 divisors (see below), whose sum is σ = 773712. Its totient is φ = 572800.

The previous prime is 669637. The next prime is 669649. The reversal of 669647 is 746966.

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

It is a cyclic number.

It is not a de Polignac number, because 669647 - 2⁸ = 669391 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 669647.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 669647.

It is not an unprimeable number, because it can be changed into a prime (669649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1604 + ... + 1977.

It is an arithmetic number, because the mean of its divisors is an integer number (96714).

2⁶⁶⁹⁶⁴⁷ is an apocalyptic number.

669647 is a deficient number, since it is larger than the sum of its proper divisors (104065).

669647 is a wasteful number, since it uses less digits than its factorization.

669647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3609.

The product of its digits is 54432, while the sum is 38.

The square root of 669647 is about 818.3196197086. The cubic root of 669647 is about 87.4880310159.

The spelling of 669647 in words is "six hundred sixty-nine thousand, six hundred forty-seven".