My brief internet search comes up with a number of three billion (six billion if counting both maternal and paternal base pairs).

A warning: Because of the way you asked, I get the impression that you may not understand the meaning of base pair versus nucleotide. DNA is a complimentary molecule where each nucleotide on one strand is complimented by a corresponding nucleotide on the other strand. This means that if you know the sequence of nucleotides on one strand, you automatically know the sequence of the other strand as well. A base pair is a pair of complimentary nucleotides - i.e. a pair where if you know one, you know the other. Because of this, the actual information in a DNA sequence depends on the number of base pairs, NOT the number of individual nucleotides, because half of the nucleotides carry no additional information.