51891 has 12 divisors (see below), whose sum is σ = 80712. Its totient is φ = 29568.

The previous prime is 51871. The next prime is 51893. The reversal of 51891 is 19815.

It is not a de Polignac number, because 51891 - 2⁵ = 51859 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51893) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 30 + ... + 323.

It is an arithmetic number, because the mean of its divisors is an integer number (6726).

2⁵¹⁸⁹¹ is an apocalyptic number.

51891 is a deficient number, since it is larger than the sum of its proper divisors (28821).

51891 is a wasteful number, since it uses less digits than its factorization.

51891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 370 (or 363 counting only the distinct ones).

The product of its digits is 360, while the sum is 24.

The square root of 51891 is about 227.7959613338. The cubic root of 51891 is about 37.2990135992.

Adding to 51891 its sum of digits (24), we get a palindrome (51915).

The spelling of 51891 in words is "fifty-one thousand, eight hundred ninety-one".