866261 has 8 divisors (see below), whose sum is σ = 961248. Its totient is φ = 774000.

The previous prime is 866231. The next prime is 866279. The reversal of 866261 is 162668.

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

It is a cyclic number.

It is not a de Polignac number, because 866261 - 2⁶ = 866197 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26 + ... + 1316.

It is an arithmetic number, because the mean of its divisors is an integer number (120156).

2⁸⁶⁶²⁶¹ is an apocalyptic number.

It is an amenable number.

866261 is a deficient number, since it is larger than the sum of its proper divisors (94987).

866261 is a wasteful number, since it uses less digits than its factorization.

866261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1363.

The product of its digits is 3456, while the sum is 29.

The square root of 866261 is about 930.7314327990. The cubic root of 866261 is about 95.3270720889.

The spelling of 866261 in words is "eight hundred sixty-six thousand, two hundred sixty-one".