February 2, 2026
Math flexes, meme wars, 64-bit chaos
The largest number representable in 64 bits
18 quintillion? Commenters say 'hold my bits' and rewrite the rules
TLDR: The post argues 64 bits can encode a tiny program that outputs a number far bigger than the usual 18 quintillion. Commenters claim that makes the question meaningless if formats are arbitrary, while others share big-number lore; the real story is the rules you choose.
A nerdy blog dives past the usual “18 quintillion” limit for 64-bit numbers by asking: what if those 64 bits encode a tiny program that spits out a truly colossal number? Cue comment-section chaos. The author toys with mind-benders like Ackermann and the Busy Beaver (a brain-melter about how long a simple machine can run), suggesting you can beat any straightforward limit by getting clever with representation. The crowd? Split between math flexers and semantics cops.
masfuerte swaggers in with an ultra-minimal “I win!” take, defining a bit pattern that represents a monstrous number, proving the point — and sparking eye-rolls. IshKebab drops the hammer: once you let any format count, the question is meaningless, because you can just decide “0 means infinity.” heyitsdaad goes full philosophy with “bits == entropy,” arguing that only raw information content matters; everything else is word games. Meanwhile, cortesoft links Scott Aaronson’s big-number lore, turning the thread into a greatest-hits tour of mathematical flexes. Sharlin’s mid-thread “oops, incorrect numbers” correction becomes an instant meme.
It’s the internet’s favorite sport: define the rules, then argue them to shreds. Some applaud the thought experiment; others say it’s a playground for clever definitions. Either way, the biggest number here is the drama.
Key Points
- •The largest 64-bit unsigned integer value is 2^64−1, available via C’s uint64_t and Rust’s u64.
- •64-bit double-precision floating point can represent finite values up to roughly 1.8×10^308 due to exponent range.
- •Considering 64-bit programs as representations changes the question; the minimal valid C program is 8 bytes long.
- •Using bc, enormous numbers (e.g., 9^999999 and 9^(9^(9^99))) can be encoded in very short expressions that fit within 64 bits.
- •The Busy Beaver function BB(n) for Turing machines is introduced to frame maximal outputs, with a note on states vs bits sizing.