6658665 has 16 divisors (see below), whose sum is σ = 11473728. Its totient is φ = 3278016.

The previous prime is 6658649. The next prime is 6658667. The reversal of 6658665 is 5668566.

It is not a de Polignac number, because 6658665 - 2⁴ = 6658649 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6658667) 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, 16879 + ... + 17268.

It is an arithmetic number, because the mean of its divisors is an integer number (717108).

Almost surely, 2^6658665 is an apocalyptic number.

6658665 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

6658665 is a deficient number, since it is larger than the sum of its proper divisors (4815063).

6658665 is a wasteful number, since it uses less digits than its factorization.

6658665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34168.

The product of its digits is 259200, while the sum is 42.

The square root of 6658665 is about 2580.4389161536. The cubic root of 6658665 is about 188.1318770642.

Subtracting from 6658665 its reverse (5668566), we obtain a palindrome (990099).

The spelling of 6658665 in words is "six million, six hundred fifty-eight thousand, six hundred sixty-five".