Yessir, 26.540 MHz LSB is actually an alternate or QSY frequency for 26.555 MHz LSB. 26.555 LSB is often really really busy.
Others include 26.545 LSB, 26.560 LSB, 26.570 LSB and others. But 26.540 MHz seems to be the most popular.
Also: 26.225 USB, 26.230 USB, 26.235 USB and of course 27.455 USB and 27.515 LSB. 26.705 AM, 26.715 AM and 27.065 AM are also very popular, next to 26.585 AM and 26.595 AM.