71866 has 4 divisors (see below), whose sum is σ = 107802. Its totient is φ = 35932.

The previous prime is 71861. The next prime is 71867. The reversal of 71866 is 66817.

71866 is nontrivially palindromic in base 15.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 66817 = 109 ⋅613.

It can be written as a sum of positive squares in only one way, i.e., 55225 + 16641 = 235^2 + 129^2 .

It is not an unprimeable number, because it can be changed into a prime (71861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 17965 + ... + 17968.

2⁷¹⁸⁶⁶ is an apocalyptic number.

71866 is a deficient number, since it is larger than the sum of its proper divisors (35936).

71866 is a wasteful number, since it uses less digits than its factorization.

71866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35935.

The product of its digits is 2016, while the sum is 28.

The square root of 71866 is about 268.0783467571. The cubic root of 71866 is about 41.5758519862.

It can be divided in two parts, 718 and 66, that added together give a square (784 = 28²).

The spelling of 71866 in words is "seventy-one thousand, eight hundred sixty-six".