866618 has 4 divisors (see below), whose sum is σ = 1299930. Its totient is φ = 433308.

The previous prime is 866581. The next prime is 866623. The reversal of 866618 is 816668.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 797449 + 69169 = 893^2 + 263^2 .

It is a plaindrome in base 13.

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 as a sum of consecutive naturals, namely, 216653 + ... + 216656.

2⁸⁶⁶⁶¹⁸ is an apocalyptic number.

866618 is a deficient number, since it is larger than the sum of its proper divisors (433312).

866618 is a wasteful number, since it uses less digits than its factorization.

866618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 433311.

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

The square root of 866618 is about 930.9231976914. The cubic root of 866618 is about 95.3401655603.

The spelling of 866618 in words is "eight hundred sixty-six thousand, six hundred eighteen".