51311 has 4 divisors (see below), whose sum is σ = 55272. Its totient is φ = 47352.

The previous prime is 51307. The next prime is 51329. The reversal of 51311 is 11315.

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 51311 - 2² = 51307 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51292 and 51301.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51341) 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, 1961 + ... + 1986.

It is an arithmetic number, because the mean of its divisors is an integer number (13818).

2⁵¹³¹¹ is an apocalyptic number.

51311 is a deficient number, since it is larger than the sum of its proper divisors (3961).

51311 is a wasteful number, since it uses less digits than its factorization.

51311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3960.

The product of its digits is 15, while the sum is 11.

The square root of 51311 is about 226.5193148497. The cubic root of 51311 is about 37.1595254858.

Adding to 51311 its reverse (11315), we get a palindrome (62626).

It can be divided in two parts, 5 and 1311, that multiplied together give a triangular number (6555 = T₁₁₄).

The spelling of 51311 in words is "fifty-one thousand, three hundred eleven".