How to Write 秭 (zǐ) — Meaning “septillion (10^24)”

Imagine a huge pile of grain (禾) that is so massive it would take your younger brother (弟) a septillion years to count. The 'septillion' meaning connects to the idea of an enormous, almost infinite amount of grain.

Write the left radical 禾 first with its vertical stroke straight and balanced, then add the right part 弟 in order: dot, left-falling stroke, horizontal, horizontal, vertical-hook, left-falling, upward-falling, vertical. A common mistake is making the right side too wide — keep both sides compact and similar in height.

While 秀 (xiù, elegant/beautiful) and 私 (sī, private/selfish) both share the 禾 radical, 秭 has the right component 弟 instead of 乃 (for 秀) or 厶 (for 私). Visually, 弟 has more strokes and a vertical hook, making 秭 look denser. Meaning-wise, 秭 is only used for the number septillion or in place names like 秭归.

秭 is rarely used in daily life; its main modern use is in the place name 秭归 (Zǐguī), a county in Hubei Province famous for being the hometown of the ancient poet Qu Yuan. It also appears in mathematics for the number 10^24, and in classical texts for extremely large numbers, but average speakers may not recognize it.

Common words containing 秭 include: 秭归 (zǐ guī) — Zigui (a county in Hubei); 万秭 (wàn zǐ) — an astronomical number; ten thousand quadrillion; 秭妹 (zǐ mèi) — sisters.