637 is an expression or abbrevation for Always and Forever

a-l-w-a-y-s=6
a-n-d=3
f-o-r-e-v-e-r=7

Anatidaephobia is defined as a pervasive, irrational fear that one is being watched by a duck. The anatidaephobic individual fears that no matter where they are or what they are doing, a duck watches.

Anatidaephobia is derived from the Greek word "anatidae", meaning ducks, geese or swans and "phobos" meaning fear.

637 meanz Always And Forever

6 = a.l.w.a.y.s
3 = a.n.d
7 = f.o.r.e.v.e.r

Also goes with the term 143wich meanz I Love You