Yes you can pay it electronically or by mailing in the 1040ES voucher with a check.
You can use the EFTPS (Electronic Federal Tax Payment System). You have to establish an account, get a PIN in the mail, submit your bank electronic transfer info, etc. Then from that website, you can log in and make any tax payments--estimates, or your Form 1040 amount due. It will let you schedule several payments ahead--up to a year's worth, I think, for individuals.
OR You can pay them at https://www.irs.gov/Payments
