51239 has 2 divisors, whose sum is σ = 51240. Its totient is φ = 51238.

The previous prime is 51229. The next prime is 51241. The reversal of 51239 is 93215.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 51239 - 2¹² = 47143 is a prime.

Together with 51241, it forms a pair of twin primes.

It is a Chen prime.

It is a plaindrome in base 12.

It is a self number, because there is not a number n which added to its sum of digits gives 51239.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51229) 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, 25619 + 25620.

It is an arithmetic number, because the mean of its divisors is an integer number (25620).

2⁵¹²³⁹ is an apocalyptic number.

51239 is a deficient number, since it is larger than the sum of its proper divisors (1).

51239 is an equidigital number, since it uses as much as digits as its factorization.

51239 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 270, while the sum is 20.

The square root of 51239 is about 226.3603322139. The cubic root of 51239 is about 37.1421365033.

The spelling of 51239 in words is "fifty-one thousand, two hundred thirty-nine".