Puebla is one of the smallest states of Mexico. With nearly 34 thousand square kilometers (13,000 sq mi), it is 21st in area within all federal units (Spanish: entidades federativas). Despite that, it is the sixth most populous state, with approximately 6 million persons. Puebla is also the second state with higher number of municipalities, only behind the state of Oaxaca. The municipalities of Puebla are grouped into seven regions.