Formal numbers
The formal numbers that you will often see in koseki and on checks and the like are as follows. These are known as 大字 DaiJi.
| 壱 | 一 |
| 弐 | 二 |
| 参 | 三 |
| 肆 | 四 |
| 伍 | 五 |
| 陸 | 六 |
| 漆 | 七 |
| 捌 | 八 |
| 玖 | 九 |
| 拾 | 十 |
| 廿 | 二十 |
| 佰 | 百 |
| 仟 | 千 |
| 萬 | 万 |
Thanks to Jim Lockhart for posting this
Big numbers
Follows American numbering conventions
| Number | 和 | scientific | English |
|---|---|---|---|
| 10,000 | 一万 | 1E+4 | ten thousand |
| 100,000 | 十万 | 1E+5 | one hundred thousand |
| 1,000,000 | 百万 | 1E+6 | one million |
| 10,000,000 | 千万 | 1E+7 | ten million |
| 100,000,000 | 一億 | 1E+8 | one hundred million |
| 1,000,000,000 | 十億 | 1E+9 | one billion |
| 10,000,000,000 | 百億 | 1E+10 | ten billion |
| 100,000,000,000 | 千億 | 1E+11 | one hundred billion |
| 1,000,000,000,000 | 一兆 | 1E+12 | one trillion |
| 10,000,000,000,000 | 十兆 | 1E+13 | ten trillion |
| 100,000,000,000,000 | 百兆 | 1E+14 | one hundred trillion |
| 1,000,000,000,000,000 | 千兆 | 1E+15 | one quadrillion |
| 10,000,000,000,000,000 | 一京 (ケイ) | 1E+16 | ten quadrillion |