51705 has 16 divisors (see below), whose sum is σ = 92160. Its totient is φ = 27504.

The previous prime is 51691. The next prime is 51713. The reversal of 51705 is 50715.

It is a happy number.

It is not a de Polignac number, because 51705 - 2⁵ = 51673 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 57 + ... + 326.

It is an arithmetic number, because the mean of its divisors is an integer number (5760).

2⁵¹⁷⁰⁵ is an apocalyptic number.

It is an amenable number.

51705 is a deficient number, since it is larger than the sum of its proper divisors (40455).

51705 is a wasteful number, since it uses less digits than its factorization.

51705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 397 (or 391 counting only the distinct ones).

The product of its (nonzero) digits is 175, while the sum is 18.

The square root of 51705 is about 227.3873347396. The cubic root of 51705 is about 37.2543949291.

Subtracting from 51705 its reverse (50715), we obtain a triangular number (990 = T₄₄).

The spelling of 51705 in words is "fifty-one thousand, seven hundred five".