Can this password type be brute forced?

[undeath]

Assuming a theoretical hash rate of 1 TH/s (which is already very fast, even for a fast hash mode) you'd be looking at about 10^43 years of cracking. Pretty sure that's well beyond the expected end of the universe.

62**35 / 1e12 / 60 / 60 / 24 / 364
1.722241326746101e+43

just for comparison, a twelve character password would take about 100 years to complete under the same circumstances
62**12 / 1e12 / 60 / 60 / 24 / 364
102.58530354592425