The gematria (numerical equivalent of the letters of the word) for V’Etchanan (ואתחנן) is 515, which is also the number of special prayers, actually more kabbalistic meditations, composed by Ramchal, Rabbi Moshe Chaim Luzatto in his book תקט”ו תפילות (Taktu Tefillot)–the gematria of Taktu also 515.
We learn that Moshe prayed 515 times for a reprieve from the decree against him entering the Holy Land, before he stood down. We’re told that God told him to not ask again even one more time, because if he did make that one more request God would have had no choice but to grant his wish. Various answers are proposed to what great negative for Bnei Yisrael and humankind in general would have occurred had he led the Jewish People into their land. Perhaps he understood that he had to choose between his own fulfillment or the fulfillment of the nation (there are textual hints that either he could have entered or the people might have entered, but not both). Another idea is that Moshe, leading the nation into Eretz Yisrael, would have immediately assumed the role of Mashiach, thrusting the world into Olam HaBah, the world-to-come, the final and stable reality-mode, but at an “inferior” state of perfection than were it to occur in its proper historical context (for which we still await and pray). In either event, Moshe chose for Bnei Yisrael rather than for his own benefit.
There is something very unique about Judaism. Unlike many other religions, we don’t elevate our greatest prophet to an unrealistic pedestal. We don’t declare Moshe Rabbenu, Moses our teacher, as “the perfect human being”, as “god”-like or in any way divine. Rather, the highest praise The Creator gives to Moshe is, “The man Moshe was very humble, more humble than any man on the face of the earth.” (Bamidbar 12:3). His very greatness was his profound self-understanding that as a human being, by definition, he was imperfect. Perhaps the one quality that is shared by every single person who has ever lived and who ever will live is imperfection. As such, Moshe was the most effective teacher and prophet because his commonality with all humanity was always in the front of his consciousness.
515 is a unique number. “5”, at the right side, represents the ה׳ חסדים, the five elements of love, while the “5” on the left represent the ה׳ גבורות, the five elements of strength and awe. Between them, nourishing both as well as supported by both of these “wings”, is “1”, אחד (Echad), the One God Who unifies all reality.
אחד יחיד ומיוחד (Echad, Yachid U’Meyuchad), One, Alone and Unique.