Number of the day: 51381

Properties of the number 51381:

51381 = 3³ × 11 × 173 is the 46125^th composite number and is not squarefree.
51381 has 3 distinct prime factors, 16 divisors, 15 antidivisors and 30960 totatives.
51381 has a triangular digit product 120 in base 10.
51381 = 6³ + 8³ + 37³ is the sum of 3 positive cubes in 1 way.
51381 = 25691² - 25690² = 8565² - 8562² = 2859² - 2850² = 2341² - 2330² = 965² - 938² = 795² - 762² = 309² - 210² = 235² - 62² is the difference of 2 nonnegative squares in 8 ways.
51381 is the sum of 2 positive triangular numbers.
51381 is the difference of 2 positive pentagonal numbers in 1 way.
51381 = 14² + 89² + 208² is the sum of 3 positive squares.
51381² = 15444² + 49005² is the sum of 2 positive squares in 1 way.
51381² is the sum of 3 positive squares.
51381 is a proper divisor of 439³⁶ - 1.
51381 = '5' + '1381' is the concatenation of 2 prime numbers.
51381 = '51' + '381' is the concatenation of 2 emirpimes.
51381 in base 58 = FFp and consists of only the digits 'F' and 'p'.

The number 51381 belongs to the following On-Line Encyclopedia of Integer Sequences (OEIS) sequences (among others):

Sequence numbers and descriptions below are taken from OEIS.
A047068: T(n,n+3), array T as in A047060.
A061422: Numbers k such that 2^(k-1) + k is prime.
A125597: a(1)=1; a(n) = Sum_{1<=k<n, gcd(k,n(n+1)/2)=1} a(k).
A295704: Number of equivalence classes of 132-avoiding permutations of [n], where two permutations are equivalent if they have the same set of pure descents.