6659665 has 16 divisors (see below), whose sum is σ = 8646912. Its totient is φ = 4904704.

The previous prime is 6659663. The next prime is 6659677. The reversal of 6659665 is 5669566.

It is not a de Polignac number, because 6659665 - 2¹ = 6659663 is a prime.

It is a super-2 number, since 2×6659665² = 88702275824450, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6659663) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3162 + ... + 4828.

It is an arithmetic number, because the mean of its divisors is an integer number (540432).

Almost surely, 2^6659665 is an apocalyptic number.

It is an amenable number.

6659665 is a deficient number, since it is larger than the sum of its proper divisors (1987247).

6659665 is a wasteful number, since it uses less digits than its factorization.

6659665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1736.

The product of its digits is 291600, while the sum is 43.

The square root of 6659665 is about 2580.6326743650. The cubic root of 6659665 is about 188.1412944904.

Subtracting from 6659665 its reverse (5669566), we obtain a palindrome (990099).

The spelling of 6659665 in words is "six million, six hundred fifty-nine thousand, six hundred sixty-five".