51139 has 4 divisors (see below), whose sum is σ = 55800. Its totient is φ = 46480.

The previous prime is 51137. The next prime is 51151. The reversal of 51139 is 93115.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 51139 - 2¹ = 51137 is a prime.

It is a Duffinian number.

51139 is a lucky number.

It is a zygodrome in base 2.

It is not an unprimeable number, because it can be changed into a prime (51131) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2314 + ... + 2335.

It is an arithmetic number, because the mean of its divisors is an integer number (13950).

2⁵¹¹³⁹ is an apocalyptic number.

51139 is a deficient number, since it is larger than the sum of its proper divisors (4661).

51139 is a wasteful number, since it uses less digits than its factorization.

51139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4660.

The product of its digits is 135, while the sum is 19.

The square root of 51139 is about 226.1393375775. The cubic root of 51139 is about 37.1179580941.

It can be divided in two parts, 51 and 139, that added together give a triangular number (190 = T₁₉).

The spelling of 51139 in words is "fifty-one thousand, one hundred thirty-nine".