866739 has 4 divisors (see below), whose sum is σ = 1155656. Its totient is φ = 577824.

The previous prime is 866737. The next prime is 866743. The reversal of 866739 is 937668.

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

It is not a de Polignac number, because 866739 - 2¹ = 866737 is a prime.

It is a D-number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 866697 and 866706.

It is not an unprimeable number, because it can be changed into a prime (866737) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 144454 + ... + 144459.

It is an arithmetic number, because the mean of its divisors is an integer number (288914).

2⁸⁶⁶⁷³⁹ is an apocalyptic number.

866739 is a deficient number, since it is larger than the sum of its proper divisors (288917).

866739 is a wasteful number, since it uses less digits than its factorization.

866739 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 288916.

The product of its digits is 54432, while the sum is 39.

The square root of 866739 is about 930.9881846726. The cubic root of 866739 is about 95.3446025876.

The spelling of 866739 in words is "eight hundred sixty-six thousand, seven hundred thirty-nine".