81718 has 16 divisors (see below), whose sum is σ = 151200. Its totient is φ = 32256.

The previous prime is 81707. The next prime is 81727.

81718 is nontrivially palindromic in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 81692 and 81701.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 43 + ... + 406.

It is an arithmetic number, because the mean of its divisors is an integer number (9450).

2⁸¹⁷¹⁸ is an apocalyptic number.

81718 is a deficient number, since it is larger than the sum of its proper divisors (69482).

81718 is a wasteful number, since it uses less digits than its factorization.

81718 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 471.

The product of its digits is 448, while the sum is 25.

The square root of 81718 is about 285.8636038393. The cubic root of 81718 is about 43.3949550649.

It can be divided in two parts, 817 and 18, that multiplied together give a triangular number (14706 = T₁₇₁).

The spelling of 81718 in words is "eighty-one thousand, seven hundred eighteen".