51481 has 2 divisors, whose sum is σ = 51482. Its totient is φ = 51480.

The previous prime is 51479. The next prime is 51487. The reversal of 51481 is 18415.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 38025 + 13456 = 195^2 + 116^2 .

It is a cyclic number.

It is not a de Polignac number, because 51481 - 2¹ = 51479 is a prime.

It is a super-2 number, since 2×51481² = 5300586722, which contains 22 as substring.

Together with 51479, it forms a pair of twin primes.

It is a nialpdrome in base 9.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51487) 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 as a sum of consecutive naturals, namely, 25740 + 25741.

It is an arithmetic number, because the mean of its divisors is an integer number (25741).

2⁵¹⁴⁸¹ is an apocalyptic number.

51481 is the 144-th centered pentagonal number.

It is an amenable number.

51481 is a deficient number, since it is larger than the sum of its proper divisors (1).

51481 is an equidigital number, since it uses as much as digits as its factorization.

51481 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 160, while the sum is 19.

The square root of 51481 is about 226.8942484948. The cubic root of 51481 is about 37.2005183571.

Adding to 51481 its reverse (18415), we get a palindrome (69896).

It can be divided in two parts, 514 and 81, that added together give a palindrome (595).

The spelling of 51481 in words is "fifty-one thousand, four hundred eighty-one".