9875
98765
98765432
9,876,543,210 9876543210
9875.
9876543
86420
93,876
The number is 9875.
987654
The largest number spelled without any repeating letters is "one thousand." Each letter in this phrase is unique, and it represents a significant value without any duplicates in its spelling. Other large numbers like "eleven" or "hundred" contain repeating letters, making "one thousand" the largest valid option.
93876
9876543210, without using any mathemeatical operations.