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920 is the third-largest idoneal number (the largest is 10X0, and the second-largest is 959).

920 is the largest idoneal number n such that n+1 is prime (although n−1 is also prime for n=920, but n−1 is also prime for n=the largest idoneal number (10X0)).

Let f(n) be the smallest multiple of n which is not Harshad number, 920 is the n<=1000 such that f(n) is largest (2EXEEEEX0).

Let f(n) be the smallest Euler-Jacobi pseudoprime to base n (not necessarily exceeding n), 920 is the n<=4000 such that f(n) is largest (2455, note that 2455 = 2^10+1, and 10 is the base of the numeral system of this wiki), and all other n<=4000 have f(n) <= 1940 (the second-largest f(n) for n<=4000 is f(16E6) = 1925, and the third-largest f(n) for n<=4000 is f(1870) = 1871).

Let f(n) be the smallest strong pseudoprime to base n (not necessarily exceeding n), 920 is the n<=2800 such that f(n) is largest (2455, note that 2455 = 2^10+1, and 10 is the base of the numeral system of this wiki), and all other n<=2800 have f(n) <= 1940 (the second-largest f(n) for n<=2800 is f(16E6) = 1925, and the third-largest f(n) for n<=2800 is f(1870) = 1871). (note that f(2888) = 2887, which is greater than f(920) = 2455)

There are no known generalized Wieferich primes to base 920, and they are conjectured not to exist.

ve Donzenal Numbers
0 - 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - X - E - 10 - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - 1X - 1E - 20 - 26 - 32 - 34 - 42 - 50 - 5X - 68 - 76 - 84 - 85 - 100 - 111 - 148 - 375 - 3XE - 5E6 - 666 - 6E4 - 771 - 920 - 1001 - 2047 - 2497 - 2E00 - 186X35
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