Code point
U+2140
Glyph appearance depends on your fonts.
U+2140
Sm<font> 2211U+2140 DOUBLE-STRUCK N-ARY SUMMATION is a Unicode 16.0.0 character in the Math Symbol category. It belongs to the Letterlike Symbols block.
Choose the representation you need, then copy its value.
U+2140
8512
⅀
⅀
E2 85 80
2140
00002140
%E2%85%80
\u2140
\u2140
\u2140
\2140