866816 has 20 divisors (see below), whose sum is σ = 1732962. Its totient is φ = 433152.

The previous prime is 866783. The next prime is 866819. The reversal of 866816 is 618668.

It can be written as a sum of positive squares in only one way, i.e., 774400 + 92416 = 880^2 + 304^2 .

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 866816.

It is not an unprimeable number, because it can be changed into a prime (866819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 335 + ... + 1358.

2⁸⁶⁶⁸¹⁶ is an apocalyptic number.

It is an amenable number.

866816 is a deficient number, since it is larger than the sum of its proper divisors (866146).

866816 is an equidigital number, since it uses as much as digits as its factorization.

866816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1711 (or 1695 counting only the distinct ones).

The product of its digits is 13824, while the sum is 35.

The square root of 866816 is about 931.0295376625. The cubic root of 866816 is about 95.3474259354.

The spelling of 866816 in words is "eight hundred sixty-six thousand, eight hundred sixteen".