866663 has 12 divisors (see below), whose sum is σ = 1053360. Its totient is φ = 709632.

The previous prime is 866653. The next prime is 866683. The reversal of 866663 is 366668.

It is not a de Polignac number, because 866663 - 2¹⁰ = 865639 is a prime.

It is a super-2 number, since 2×866663² = 1502209511138, which contains 22 as substring.

It is a nialpdrome in base 10.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 866663.

It is not an unprimeable number, because it can be changed into a prime (866623) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 743 + ... + 1511.

It is an arithmetic number, because the mean of its divisors is an integer number (87780).

2⁸⁶⁶⁶⁶³ is an apocalyptic number.

866663 is a deficient number, since it is larger than the sum of its proper divisors (186697).

866663 is a wasteful number, since it uses less digits than its factorization.

866663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 806 (or 799 counting only the distinct ones).

The product of its digits is 31104, while the sum is 35.

The square root of 866663 is about 930.9473669333. The cubic root of 866663 is about 95.3418157427.

The spelling of 866663 in words is "eight hundred sixty-six thousand, six hundred sixty-three".