He has Erdős number 2 due to his 2010 collaboration with Mark K. Goldberg.
It covers his unusual career, his personal life, and many of his recurring jokes and anecdotes, including that of Erdős numbers.
Lucky Number Slevin | Reynolds number | Mach number | serial number | Random number generation | International Standard Book Number | prime number | Personal identification number | number | Two in a Million/You're My Number One | Social Security number | Rikki Don't Lose That Number | Prime number | Premium-rate telephone number | Jackass Number Two | Opus number | Number Girl | List of WTA number 1 ranked players | Lah number | Erdős number | Emergency telephone number | Betti number | You're My Number One | What's Your Number? | The Number 23 | The Murderer Lives at Number 21 | real number | opus number | natural number | National identification number |
Murty has Erdős number 1, and has collaborated with dozens of other researchers, including frequent joint work with his brother, V. Kumar Murty.
Ho has an Erdős number of 4: Yu-Chi Ho - Demosthenis Teneketzis - Wayne Stark - Robert McEliece - Paul Erdős
The Erdős-Number project at Oakland University maintains a website tracking the Erdős numbers of scientists world-wide.