19. Reng, 152 bytes

#v`16 "<" 6/b0\ .q@#;n4"14""
#>3N9@15o|R"12"*^*ttt*~++%
#=|
print((1/2and 9 or 13)-(0and+4)^1<<65>>62);# =#;print(17)
#       ~nJ<
#
#gg99ddi2` |1|1+6

I added another #\n so that retina would cooperate. Here's how it works:

# redefines v to push 0, the default TOS. Then, it negates the TOS (`), pushes 1 and 6, the character of <, pushes 6 again, and mirrors upwards with /, colliding with the other `, which negates the 6. Then, it hits the <, pushes J (base 36 for 19), then outputs it as a number, finally terminating (~).

Escapes in between 2 and `; and # and g.

1. Try it online!—Python 3
2. Try it online!—V
3. Try it online!—Minkolang
4. Try it online!—><>
5. Try it online!—Python 2
6. Try it online!—SMBF
7. Ethproductions—Japt
8. Try it online!—Retina
9. Try it online!—Perl
10. Try it online!—Befunge 93
11. Try it online!—Befunge 98
12. Try it online!—Fission
13. Try it online!—Ruby
14. Try it online!—Turtléd
15. Try it online!—Haystack
16. Try it online!—Pyth
17. Try it online!—Julia
18. Cardinal
19. JSFiddle—Reng