6665649 has 8 divisors (see below), whose sum is σ = 9410400. Its totient is φ = 4182336.

The previous prime is 6665639. The next prime is 6665669. The reversal of 6665649 is 9465666.

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

It is not a de Polignac number, because 6665649 - 2¹² = 6661553 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 6665649.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6665639) 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, 65299 + ... + 65400.

It is an arithmetic number, because the mean of its divisors is an integer number (1176300).

Almost surely, 2^6665649 is an apocalyptic number.

It is an amenable number.

6665649 is a deficient number, since it is larger than the sum of its proper divisors (2744751).

6665649 is a wasteful number, since it uses less digits than its factorization.

6665649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130719.

The product of its digits is 233280, while the sum is 42.

The square root of 6665649 is about 2581.7918196477. The cubic root of 6665649 is about 188.1976286789.

The spelling of 6665649 in words is "six million, six hundred sixty-five thousand, six hundred forty-nine".