866761 has 15 divisors (see below), whose sum is σ = 1067181. Its totient is φ = 703836.

The previous prime is 866759. The next prime is 866777. The reversal of 866761 is 167668.

The square root of 866761 is 931.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 866761 - 2¹ = 866759 is a prime.

It is a super-2 number, since 2×866761² = 1502549262242, which contains 22 as substring.

It is a Duffinian number.

It is a plaindrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (866161) 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 14 ways as a sum of consecutive naturals, for example, 45610 + ... + 45628.

2⁸⁶⁶⁷⁶¹ is an apocalyptic number.

866761 is the 931-st square number.

866761 is the 466-th centered octagonal number.

It is an amenable number.

866761 is a deficient number, since it is larger than the sum of its proper divisors (200420).

866761 is an frugal number, since it uses more digits than its factorization.

866761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66 (or 26 counting only the distinct ones).

The product of its digits is 12096, while the sum is 34.

The cubic root of 866761 is about 95.3454092755.

The spelling of 866761 in words is "eight hundred sixty-six thousand, seven hundred sixty-one".