6635665 has 4 divisors (see below), whose sum is σ = 7962804. Its totient is φ = 5308528.

The previous prime is 6635663. The next prime is 6635669. The reversal of 6635665 is 5665366.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 725904 + 5909761 = 852^2 + 2431^2 .

It is a cyclic number.

It is not a de Polignac number, because 6635665 - 2¹ = 6635663 is a prime.

It is a Duffinian number.

6635665 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (6635663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 663562 + ... + 663571.

It is an arithmetic number, because the mean of its divisors is an integer number (1990701).

Almost surely, 2^6635665 is an apocalyptic number.

It is an amenable number.

6635665 is a deficient number, since it is larger than the sum of its proper divisors (1327139).

6635665 is a wasteful number, since it uses less digits than its factorization.

6635665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1327138.

The product of its digits is 97200, while the sum is 37.

The square root of 6635665 is about 2575.9784548788. The cubic root of 6635665 is about 187.9150155350.

Subtracting from 6635665 its reverse (5665366), we obtain a cube (970299 = 99³).

It can be divided in two parts, 663 and 5665, that added together give a triangular number (6328 = T₁₁₂).

The spelling of 6635665 in words is "six million, six hundred thirty-five thousand, six hundred sixty-five".