parseint

An ES-spec-compliant `parseInt` shim/polyfill/replacement that works as far down as ES3

number.issafeinteger

An ES-spec-compliant Number.isSafeInteger shim/polyfill/replacement that works as far down as ES3

number.isinteger

An ES-spec-compliant Number.isInteger shim/polyfill/replacement that works as far down as ES3