66718 has 4 divisors (see below), whose sum is σ = 100080. Its totient is φ = 33358.

The previous prime is 66713. The next prime is 66721. The reversal of 66718 is 81766.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 81766 = 2 ⋅40883.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66713) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16678 + ... + 16681.

It is an arithmetic number, because the mean of its divisors is an integer number (25020).

2⁶⁶⁷¹⁸ is an apocalyptic number.

66718 is a deficient number, since it is larger than the sum of its proper divisors (33362).

66718 is a wasteful number, since it uses less digits than its factorization.

66718 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33361.

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

The square root of 66718 is about 258.2982771913. The cubic root of 66718 is about 40.5584179572.

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

The spelling of 66718 in words is "sixty-six thousand, seven hundred eighteen".