There's a related article linked in OP that answers your questions: https://developers.google.com/web/updates/2018/05/bigint

When mixing Number and BigInt, abstract equality (==) works fine, but strict equality (===) is always false, since they are two different primitive types.

Most bitwise operators are allowed, so long as all operands are the same type (Number or BigInt). The only exception is zero-fill right shift (>>>) since that doesn't make any sense with respect to BigInts.

From my console: (node 10 with --harmony-bigint)

  > 1n == 1
  true
  > 1n === 1
  false
  > 12345n >> 1
  TypeError: Cannot mix BigInt and other types, use explicit conversions
  > 12345n >> 1n
  6172n
  > 12345n >>> 1n
  TypeError: BigInts have no unsigned right shift, use >> instead