Innodb status montior and Thread information (2 replies)

Hi
when I watch "show Innodb engine status "
i see somethign liek this


Main thread process no. 12537, id 1287936320, state: flushing buffer pool pages

now ps out put :

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
12537 mysql 15 0 16.7g 16g 6764 S 49.4 62.1 939:45.17 mysqld


so main thread process number i know its the process of mysqld

but dont understand, from where this id is comming from ?
"id 1287936320"
whats this id ??
Thanks for your help.