$ perl -Mstrict -wE 'use Number::Spell; say spell_number(100010001001)'
one hundred billion ten million one thousand one

$ perl -Mstrict -wE 'use Lingua::EN::Numbers qw{num2en}; say num2en(100010001001)'
one hundred billion, ten million, one thousand and, one

$ perl -Mstrict -wE 'use Util::Number; say conv_num_to_text(100010001001)'
one hundred billion, ten million, one thousand and one