Well, it depends on what vaporization means to you. There are two answers to that. One is boiling away the water in your body leaving bones and the other is completely breaking every compound in your body.
The first one happens at 212 F and requires a lot of heat(around 136 million Joules). An atomic blast is hotter than 212 F. It’s like a lot hotter. Add around 90 million F.
Now, it is said that the amount of heat energy required to vaporize a human is around 3 GJ. That’s 3 with 9 zeros. The average human is 154 lbs(70kg). Using the heat transfer formula, we get:
(Temperature req)= (heat energy)/(mass of human body)(specific heat of human body(3500 J/kg.C)) - (temperature of human body).
T= 3000000000/703500 - 37
T= 12245 C( approx.)
Temperature required = 22073 F
Therefore, chances are you are going to be completely vaporized in an atomic blast if you’re at ground zero.Well, the good thing is you won’t need a funeral.
P.S.: We are not taking distance as a factor in this question. If you are away from ground zero, distance begins to matter. The temperature required to vaporize you increases with distance.