A hashrate of 1.42 EH/s, really? According to http://bravenewcoin.com/news/number-of-bitcoin-miners-far-higher-than-popular-estimates/ there are 100,000 miners and blockchain.info claims a hashrate of 1.42 EH/s.

How is it possible to be mining on Bitcoin at a hashrate of 1.42 EH/s with just 100,000 miners?

That would yield 14.2 TH/s per miner, while best ASICs are performing around 1 TH/s https://en.bitcoin.it/wiki/Mining_hardware_comparison
A miner should not be correlated with a device. I can have 10 devices and I will still be a single miner from the perspective of the pool. I can have a mining farm with thousand devices and I can still look like a single miner to the pool.

Also note that a miner, in the above sense, is just a person that provides hashing power to a pool that runs a mining node; i.e. there are much less mining nodes.