Number of the day: 71771

Properties of the number 71771:

71771 = 7 × 10253 is semiprime and squarefree.
71771 has 2 distinct prime factors, 4 divisors, 17 antidivisors and 61512 totatives.
71771 has a prime digit sum 23 in base 10.
Reversing the decimal digits of 71771 results in an emirpimes.
71771 = 35886² - 35885² = 5130² - 5123² is the difference of 2 nonnegative squares in 2 ways.
71771 is the difference of 2 positive pentagonal numbers in 2 ways.
71771 = 11² + 19² + 267² is the sum of 3 positive squares.
71771² = 24675² + 67396² is the sum of 2 positive squares in 1 way.
71771² is the sum of 3 positive squares.
71771 is a divisor of 1931²² - 1.
71771 is an emirpimes in (at least) the following bases: 3, 5, 6, 10, 11, 15, 24, 31, 32, 33, 34, 39, 43, 46, 48, 53, 55, 56, 61, 64, 67, 68, 74, 85, 87, 88, 91, 93, and 94.
71771 is palindromic in (at least) the following bases: 78, and 80.
71771 consists of only the digits '1' and '7'.

The number 71771 belongs to the following On-Line Encyclopedia of Integer Sequences (OEIS) sequences (among others):

Sequence numbers and descriptions below are taken from OEIS.
A079465: Numbers n such that the "inventory" A063850 of n is a perfect square.
A107287: a(n) = a(n-1)+a(n-2)-a(n-3)+a(n-5), n>7.