866605 has 8 divisors (see below), whose sum is σ = 1073664. Its totient is φ = 670800.

The previous prime is 866581. The next prime is 866623. The reversal of 866605 is 506668.

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

It is not a de Polignac number, because 866605 - 2⁵ = 866573 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is a plaindrome in base 13.

It is a congruent 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, 2641 + ... + 2950.

It is an arithmetic number, because the mean of its divisors is an integer number (134208).

2⁸⁶⁶⁶⁰⁵ is an apocalyptic number.

It is an amenable number.

866605 is a deficient number, since it is larger than the sum of its proper divisors (207059).

866605 is a wasteful number, since it uses less digits than its factorization.

866605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5627.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 866605 is about 930.9162153492. The cubic root of 866605 is about 95.3396888303.

The spelling of 866605 in words is "eight hundred sixty-six thousand, six hundred five".