8640665 has 8 divisors (see below), whose sum is σ = 11311488. Its totient is φ = 6284080.

The previous prime is 8640601. The next prime is 8640679. The reversal of 8640665 is 5660468.

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

It is not a de Polignac number, because 8640665 - 2⁶ = 8640601 is a prime.

It is a super-2 number, since 2×8640665² = 149322183284450, which contains 22 as substring.

It is a Duffinian 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 7 ways as a sum of consecutive naturals, for example, 78497 + ... + 78606.

It is an arithmetic number, because the mean of its divisors is an integer number (1413936).

Almost surely, 2^8640665 is an apocalyptic number.

It is an amenable number.

8640665 is a deficient number, since it is larger than the sum of its proper divisors (2670823).

8640665 is a wasteful number, since it uses less digits than its factorization.

8640665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157119.

The product of its (nonzero) digits is 34560, while the sum is 35.

The square root of 8640665 is about 2939.5008079604. The cubic root of 8640665 is about 205.2023779754.

It can be divided in two parts, 864066 and 5, that multiplied together give a triangular number (4320330 = T₂₉₃₉).

The spelling of 8640665 in words is "eight million, six hundred forty thousand, six hundred sixty-five".