176 Jean-Marie De Koninck
7 560
the smallest highly composite number which is not superabundant (see the
number 110 880): it is the 20th highly composite number (see the number 180).
7 641
the only four digit self replicating number (see the number 954).
7 647
the 16th Keith number (see the number 197).
7 696
the fourth number whose square can be written as the sum of three fourth
powers: 7 6962 = 484 + 604 + 804 (see the number 481).
7 741
the 31rst Lucas prime number (see the number 613).
7 744 (= 882)
the largest four digit perfect square which has only two distinct digits (see the
number 1 444).
7 755
the
17th
number n such that n ·
2n
1 is prime (see the number 115).
7 776
the fourth number n 2 such that
σ(n) + φ(n)
γ(n)2
is an integer (see the number
588).
7 785
the fourth number n such that

p≤pn
p is a perfect square: here

p≤p7785
p =
17
0982
(see the number 2 474).
7 909
the
17th
Keith number (see the number 197).
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