65866 has 4 divisors (see below), whose sum is σ = 98802. Its totient is φ = 32932.

The previous prime is 65851. The next prime is 65867. The reversal of 65866 is 66856.

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

It can be written as a sum of positive squares in only one way, i.e., 65025 + 841 = 255^2 + 29^2 .

It is not an unprimeable number, because it can be changed into a prime (65867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16465 + ... + 16468.

2⁶⁵⁸⁶⁶ is an apocalyptic number.

65866 is a deficient number, since it is larger than the sum of its proper divisors (32936).

65866 is a wasteful number, since it uses less digits than its factorization.

65866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32935.

The product of its digits is 8640, while the sum is 31.

The square root of 65866 is about 256.6437219181. The cubic root of 65866 is about 40.3850318697.

Subtracting 65866 from its reverse (66856), we obtain a triangular number (990 = T₄₄).

The spelling of 65866 in words is "sixty-five thousand, eight hundred sixty-six".