65681 has 8 divisors (see below), whose sum is σ = 81984. Its totient is φ = 51120.

The previous prime is 65677. The next prime is 65687. The reversal of 65681 is 18656.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 65681 - 2² = 65677 is a prime.

It is a super-2 number, since 2×65681² = 8627987522, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 65681.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 65681.

It is not an unprimeable number, because it can be changed into a prime (65687) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 350 + ... + 503.

It is an arithmetic number, because the mean of its divisors is an integer number (10248).

2⁶⁵⁶⁸¹ is an apocalyptic number.

It is an amenable number.

65681 is a deficient number, since it is larger than the sum of its proper divisors (16303).

65681 is a wasteful number, since it uses less digits than its factorization.

65681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 871.

The product of its digits is 1440, while the sum is 26.

The square root of 65681 is about 256.2830466496. The cubic root of 65681 is about 40.3471861590.

It can be divided in two parts, 656 and 81, that added together give a palindrome (737).

The spelling of 65681 in words is "sixty-five thousand, six hundred eighty-one".