865966 has 4 divisors (see below), whose sum is σ = 1298952. Its totient is φ = 432982.

The previous prime is 865957. The next prime is 865979. The reversal of 865966 is 669568.

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

It is a super-2 number, since 2×865966² = 1499794226312, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 216490 + ... + 216493.

It is an arithmetic number, because the mean of its divisors is an integer number (324738).

2⁸⁶⁵⁹⁶⁶ is an apocalyptic number.

865966 is a deficient number, since it is larger than the sum of its proper divisors (432986).

865966 is a wasteful number, since it uses less digits than its factorization.

865966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 432985.

The product of its digits is 77760, while the sum is 40.

The square root of 865966 is about 930.5729417945. The cubic root of 865966 is about 95.3162498390.

The spelling of 865966 in words is "eight hundred sixty-five thousand, nine hundred sixty-six".