8165665 has 4 divisors (see below), whose sum is σ = 9798804. Its totient is φ = 6532528.

The previous prime is 8165653. The next prime is 8165671. The reversal of 8165665 is 5665618.

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 4661281 + 3504384 = 2159^2 + 1872^2 .

It is a cyclic number.

It is not a de Polignac number, because 8165665 - 2⁷ = 8165537 is a prime.

It is a Duffinian number.

8165665 is a lucky number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 816562 + ... + 816571.

It is an arithmetic number, because the mean of its divisors is an integer number (2449701).

Almost surely, 2^8165665 is an apocalyptic number.

It is an amenable number.

8165665 is a deficient number, since it is larger than the sum of its proper divisors (1633139).

8165665 is a wasteful number, since it uses less digits than its factorization.

8165665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1633138.

The product of its digits is 43200, while the sum is 37.

The square root of 8165665 is about 2857.5627727138. The cubic root of 8165665 is about 201.3711203313.

Subtracting from 8165665 its product of digits (43200), we obtain a triangular number (8122465 = T₄₀₃₀).

The spelling of 8165665 in words is "eight million, one hundred sixty-five thousand, six hundred sixty-five".