65818 has 4 divisors (see below), whose sum is σ = 98730. Its totient is φ = 32908.

The previous prime is 65809. The next prime is 65827. The reversal of 65818 is 81856.

It is a happy number.

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

It is an interprime number because it is at equal distance from previous prime (65809) and next prime (65827).

It can be written as a sum of positive squares in only one way, i.e., 45369 + 20449 = 213^2 + 143^2 .

It is an Ulam number.

It is an alternating number because its digits alternate between even and odd.

It is a plaindrome in base 15.

It is an unprimeable number.

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, 16453 + ... + 16456.

2⁶⁵⁸¹⁸ is an apocalyptic number.

65818 is a deficient number, since it is larger than the sum of its proper divisors (32912).

65818 is a wasteful number, since it uses less digits than its factorization.

65818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32911.

The product of its digits is 1920, while the sum is 28.

The square root of 65818 is about 256.5501900214. The cubic root of 65818 is about 40.3752192571.

It can be divided in two parts, 658 and 18, that added together give a palindrome (676).

The spelling of 65818 in words is "sixty-five thousand, eight hundred eighteen".