This Quartz piece explores why men now outnumber women by 60 million, the highest ever recorded:
"In 2013, 49.59% of the global population were women. 81 countries had a majority of women, 37 countries had a majority of men... The most populous countries in the world are also highly imbalanced: China has nearly 50 million more men than women, India 43 million, accounting for 76% of the male surplus worldwide...The most gender imbalanced states in 2013 were all found on the Arabian Peninsula, Qatar being the most extreme. Less than one quarter of all people who lived in Qatar in 2013 were women... The former Soviet states are notorious for men's short life expectancy, which is largely attributed to alcohol-related deaths. Strikingly, Russia currently has more than twice as many women than men above the age of 65... Disruptive events such as wars and genocides show in the data as well. Since they tend to claim more men's lives than women's, the population's sex ratio usually shifts female."
Their dynamic infographic and more information can be found here.