One in five Americans (20 percent) correctly estimates that Hillary Clinton was to turn 60 years old on Friday, according to a FOX News poll. In fact, a scant 11 percent of voters think the senator from New York is older than 60, while a majority (57 percent) guess a variety of ages younger than 60.

Opinion Dynamics Corp. conducted the national telephone poll of 900 registered voters for FOX News from Oct. 23 to Oct. 24. The poll has a 3-point error margin.

Click here to view the full results of the poll.

Interestingly, men (21 percent) are just about as likely as women (19 percent) to peg Hillary’s age at 60.

Oddly, Democrats (8 percent) are less likely than Republicans (13 percent) to correctly guess Clinton’s age.

The Democratic presidential contender’s contemporaries (voters aged 55 to 64) are the mostly likely age group to accurately estimate her age (35 percent).

When asked to pick the most appropriate theme song for a hypothetical birthday party, the most popular of the offered choices is "If I Ruled the World" by Tony Bennett (32 percent), followed closely by "I am Woman" by Helen Reddy (31 percent). "Stand by Your Man" by Tammy Wynette trailed in third position at 19 percent.

Democrats are more likely to think the "I am Woman" applies best to Hillary’s birthday party (41 percent), while among Republicans, the "If I Ruled the World" theme is the top choice (39 percent).