866981 has 4 divisors (see below), whose sum is σ = 879264. Its totient is φ = 854700.

The previous prime is 866969. The next prime is 867001. The reversal of 866981 is 189668.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 866981 - 2⁶ = 866917 is a prime.

It is a super-2 number, since 2×866981² = 1503312108722, which contains 22 as substring.

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 866981.

It is not an unprimeable number, because it can be changed into a prime (866941) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 6035 + ... + 6176.

It is an arithmetic number, because the mean of its divisors is an integer number (219816).

2⁸⁶⁶⁹⁸¹ is an apocalyptic number.

It is an amenable number.

866981 is a deficient number, since it is larger than the sum of its proper divisors (12283).

866981 is a wasteful number, since it uses less digits than its factorization.

866981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12282.

The product of its digits is 20736, while the sum is 38.

The square root of 866981 is about 931.1181450278. The cubic root of 866981 is about 95.3534754035.

The spelling of 866981 in words is "eight hundred sixty-six thousand, nine hundred eighty-one".