How many zeros are there in one trillion?

None of these

One Trillion: Has 12 zeros (1,000,000,000,000) or $10^{12}$ .

Quadrillion: $10^{15}$ (15 zeros).

Quintillion: $10^{18}$ (18 zeros).

Sextillion: Has 21 zeros.

A trillion equals a thousand billions or a million millions.

Counting to one trillion seconds would take approximately 32,000 years.