100010001

100010001 is a binary numeral consisting of nine digits. Interpreted in base-2, it equals the decimal number 273.

Written as a binary palindrome, it reads the same forwards and backwards, a symmetry that is preserved in 9-bit representation.

The set bits occur at positions 8, 4, and 0 (counting from zero on the right), giving the value 2^8 + 2^4 + 2^0 = 256 + 16 + 1 = 273.

In hexadecimal, 273 is 0x111, and this binary pattern corresponds to that value when leading zeros are omitted.

In mathematical contexts, 100010001 is cited as an example of a binary palindrome and of numbers with sparse bit sets. It is sometimes used as a test pattern for palindromic detection algorithms and in digital logic designs to illustrate symmetric bit patterns.