6689661 has 8 divisors (see below), whose sum is σ = 9730464. Its totient is φ = 4054320.

The previous prime is 6689659. The next prime is 6689681. The reversal of 6689661 is 1669866.

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

It is not a de Polignac number, because 6689661 - 2¹ = 6689659 is a prime.

6689661 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6689611) 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, 101326 + ... + 101391.

It is an arithmetic number, because the mean of its divisors is an integer number (1216308).

Almost surely, 2^6689661 is an apocalyptic number.

It is an amenable number.

6689661 is a deficient number, since it is larger than the sum of its proper divisors (3040803).

6689661 is a wasteful number, since it uses less digits than its factorization.

6689661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 202731.

The product of its digits is 93312, while the sum is 42.

The square root of 6689661 is about 2586.4378979593. The cubic root of 6689661 is about 188.4233424317.

The spelling of 6689661 in words is "six million, six hundred eighty-nine thousand, six hundred sixty-one".