51761 has 4 divisors (see below), whose sum is σ = 52224. Its totient is φ = 51300.

The previous prime is 51749. The next prime is 51767. The reversal of 51761 is 16715.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 16715 = 5 ⋅3343.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51761 is a prime.

It is a super-2 number, since 2×51761² = 5358402242, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (51767) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 56 + ... + 326.

It is an arithmetic number, because the mean of its divisors is an integer number (13056).

2⁵¹⁷⁶¹ is an apocalyptic number.

It is an amenable number.

51761 is a deficient number, since it is larger than the sum of its proper divisors (463).

51761 is a wasteful number, since it uses less digits than its factorization.

51761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 462.

The product of its digits is 210, while the sum is 20.

The square root of 51761 is about 227.5104393209. The cubic root of 51761 is about 37.2678397500.

The spelling of 51761 in words is "fifty-one thousand, seven hundred sixty-one".