818665 has 4 divisors (see below), whose sum is σ = 982404. Its totient is φ = 654928.

The previous prime is 818659. The next prime is 818683. The reversal of 818665 is 566818.

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 522729 + 295936 = 723^2 + 544^2 .

It is a cyclic number.

It is not a de Polignac number, because 818665 - 2¹³ = 810473 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 818665.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 81862 + ... + 81871.

It is an arithmetic number, because the mean of its divisors is an integer number (245601).

2⁸¹⁸⁶⁶⁵ is an apocalyptic number.

It is an amenable number.

818665 is a deficient number, since it is larger than the sum of its proper divisors (163739).

818665 is a wasteful number, since it uses less digits than its factorization.

818665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163738.

The product of its digits is 11520, while the sum is 34.

The square root of 818665 is about 904.8010831116. The cubic root of 818665 is about 93.5481940530.

The spelling of 818665 in words is "eight hundred eighteen thousand, six hundred sixty-five".