Sunday, January 14, 2018

Number of the day: 7277

Alfred Tarski was born on this day 117 years ago.

Properties of the number 7277:

7277 is a cyclic number.
7277 = 19 × 383 is semiprime and squarefree.
7277 has 2 distinct prime factors, 4 divisors, 31 antidivisors and 6876 totatives.
7277 has a prime digit sum 23 in base 10.
Reversing the decimal digits of 7277 results in a prime.
7277 = 36392 - 36382 = 2012 - 1822 is the difference of 2 nonnegative squares in 2 ways.
7277 is the difference of 2 positive pentagonal numbers in 2 ways.
7277 = 62 + 292 + 802 is the sum of 3 positive squares.
72772 is the sum of 3 positive squares.
7277 is a proper divisor of 15316 - 1.
7277 = '7' + '277' is the concatenation of 2 prime numbers.
7277 is an emirpimes in (at least) the following bases: 5, 7, 16, 17, 23, 25, 29, 32, 34, 37, 45, 46, 55, 57, 59, 60, 61, 64, 65, 66, 67, 69, 71, 72, 73, 76, 77, 78, 79, 81, 85, 87, 93, and 94.
7277 is palindromic in (at least) the following bases: 36, 68, and -75.
7277 consists of only the digits '2' and '7'.
7277 in base 15 = 2252 and consists of only the digits '2' and '5'.
7277 in base 35 = 5ww and consists of only the digits '5' and 'w'.
7277 in base 36 = 5m5 and consists of only the digits '5' and 'm'.

The number 7277 belongs to the following On-Line Encyclopedia of Integer Sequences (OEIS) sequences (among others):

Sequence numbers and descriptions below are taken from OEIS.
A049114: 2-ranks of difference sets constructed from Glynn type II hyperovals.
A050969: Discriminants of real quadratic fields with class number 1 and related continued fraction period length of 20.
A116698: Expansion of -(1-x+3*x^2+x^3)/((x^2+x-1)*(2*x^2+1)).
A186656: Total number of n-digit numbers requiring 5 positive biquadrates in their representation as sum of biquadrates.
A187265: Number of nonempty subsets of {1, 2, ..., n} with <= 4 pairwise coprime elements.
A266338: G.f. = b(2)*b(4)*b(6)/(x^8-x^3-x+1), where b(k) = (1-x^k)/(1-x).
A284921: Numbers with digits 2 and 7 only.
A285338: Expansion of Product_{k>=1} (1 + x^(5*k-4))^(5*k-4).
A292094: Consider Watanabe's 3-shift tag system {00/1011} applied to the word (100)^n; a(n) = position of the longest word in the orbit, or -1 if the orbit is unbounded.
A292737: Numbers in which 7 outnumbers all other digits together.

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