#480000634201463866098507671986857600456541966537081502199043384166162825944898410342464888436431677232893465794808733646522220208867979650020658090378479123174293639201816434282724741785738156488117739769310106814816334390595146211324545793014802253484550369254600003272879909905790941622207173721151418827470934074912600834751476879913995643495080883246764912768904959844637450#
[S],                                #encode all of the bytes of this program (except the first line) into a single integer, and store it in S.
#35#                                #push ordinal value of "#".

[L0]                                #determine the length of S in decimal digits. L will contain the final result.
[TS]                                #put a copy of S in T, which we will destroy
w[LL1+][T#10#T/],0Tg}               #while T > 0: increment L, remove a digit from T

[C1L-]                              #push the character equivalent of each digit of S onto the stack. For C from L-1 to 0...
{
   #10#C#10#eS/%#48#+[C1C-]         #get the C'th least significant digit, add 48 to get its equivalent character, then push onto the stack.
,L}
#35#                                #push ordinal value of "#"

[L0]                                #determine the number of bytes of S. L will contain the final result.
[TS]
w[LL1+][T8T>],0Tg}                  #while T > 0: increment L, right shift T by a byte

[C0]                                #extract the C'th least significant byte from S and push it to the stack. For C from 0 to L...
{
    #256#C8*S>%[C1C+]               #right-shift S by C bytes and push the smallest 8 bits.
,L}

c                                   #print.