51686 has 8 divisors (see below), whose sum is σ = 79464. Its totient is φ = 25200.

The previous prime is 51683. The next prime is 51691. The reversal of 51686 is 68615.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51683) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 215 + ... + 386.

It is an arithmetic number, because the mean of its divisors is an integer number (9933).

2⁵¹⁶⁸⁶ is an apocalyptic number.

51686 is a deficient number, since it is larger than the sum of its proper divisors (27778).

51686 is a wasteful number, since it uses less digits than its factorization.

51686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 646.

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

The square root of 51686 is about 227.3455519688. The cubic root of 51686 is about 37.2498310879.

It can be divided in two parts, 51 and 686, that added together give a palindrome (737).

The spelling of 51686 in words is "fifty-one thousand, six hundred eighty-six".