Prolog predicate equivalent to formatInteger()?

General
1

I just found this nice nugget inside SWI-Prolog devel C code:

static char *	formatInteger(PL_locale *locale, int div, int radix,
			     bool smll, Number n, Buffer out);

Is there a Prolog predicate equivalent do call this, maybe some
predicate with a name ‘$…’? So that it could be used directly without
a detour over format/2, eliminating the dependency on format/2?

Many languages have this primordially before format/2. I assume
in SWI-Prolog its calling mpz_get_str() from GMP, when GMP is
available? Example of a similar API in JavaScript:

radix Optional
BigInt.prototype.toString() - JavaScript | MDN