366 Jean-Marie De Koninck
1 968 188 556 461
the smallest prime number which is followed by at least 600 consecutive compos-
ite numbers (in fact here by exactly 601 composite numbers); see the number
370 261.
2 094 447 251 857
the seventh number having two representations as the sum of two co-prime
fourth powers:
2 094 447 251 857 =
12034
+
764
=
11764
+
6534
(see the number 635 318 657).
2 152 302 898 747
the smallest strong pseudoprime in bases 2, 3, 5, 7 and 11 (Riesel [173], p. 91).
2 207 984 167 552 (= 587)
the seventh number n 1 whose sum of digits is equal to
7

n (see the number
612 220 032).
2 404 879 675 441
the 18th Euler number (see the number 272).
2 615 428 934 649
the only number 2 which is equal to the sum of the factorials of its digits
in base 16: here 2 615 428 934 649 = [2, 6, 0, 15, 3, 11, 6, 6, 11, 15, 9]16 = 2! + 6! +
0!+15!+3!+11!+6!+6!+11!+15!+9! (see also the numbers 145 and 40 472).
2 682 923 295 390 (= 2 · 3 · 5 · 13 · 23 · 47 · 113 · 199 · 283)
the 15th ideal number (see the number 390).
2 710 954 639 361
the smallest prime factor of F13 =
2213
+ 1 (see the number 70 525 124 609).
2 733 834 545 701 (= 74 · 30893 · 36857)
a 6-hyperperfect number, possibly the fifth (see the number 301).
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