Looks like each girl got a number for them, this is what the concert goers could gather...
01 = Hagiwara Mai
03 = Sudou Maasa
05 = Ogawa Makoto
07 = Tanaka Reina
10 = Tokunaga Chinami
11 = Kamei Eri
14 = Ishikawa Rika
21 = Niigaki Risa
22 = Tsuji Nozomi
29 = Tsugunaga Momoko
32 = Fujimoto Miki
33 = Okada Yui
34 = Miyoshi Erika
37 = Michishige Sayumi
43 = Shimizu Saki
44 = Yoshizawa Hitomi
51 = Kago Ai
53 = Konno Asami
55 = Umeda Erika
58 = Kusumi Koharu
61 = Murakami Megumi
66 = Suzuki Airi
73 = Okai Chisato
74 = Nakajima Saki
81 = Takahashi Ai
84 = Yajima Maimi
90 = Kumai Yurina
And I looked up possible pronunciations on the numbers from Rikai...
1 = ichi, itsu, hito, hito+tsu, kazu, i, iru, katsu, ten, hajime, hi, makoto
2 = ni, ji, futa, futa+tsu, futata+bi, oto, tsugu, nii, ha, fu, fuda, futatsu, wa
3 = san, zou, mi, mi+tsu, ka, sa, sai, sae, sabu, za, zae, zabu, sou, zo, tada, mitsu, min, mo, ya
4 = shi, yo, yo+tsu, yon, a, tsu, yotsu
5 = go, itsu, itsu+tsu, i, sa, satsu, chi, fu, mi, me
6 = roku, riku, mu, mu+tsu, mui, ku, mutsu, ro, rotsu
7 = shichi, nana, nana+tsu, nano, shi, na, hichi
8 = hachi, ya, ya+tsu, you, na, ha, hatsu, yachi, yatsu, hachigashira
9 = kyuu, ku, kokono, kokono+tsu, ichijiku, ichinoku, kono, hisashi
10 = juu, ji, ju, too, to, i, ka, gi, sa, shi, so, sou, chi, tou, ne, ma, ru, wa
And here's my takes on some of the numbers...
05 = 0gawa Ma5to
(I don't know if you can use go for ko )07 = Tanaka 07
11 = Kame1 Er1
(uses 1 as I)14 = 14kawa Rika
21 = 21gaki Risa
22 = 22 Nozomi
32 = 3ki 2jimoto
34 = 34shi Erika
37 = 3chi7ge Sayumi
43 = 43zu Saki
44 = 44zawa Hitomi
51 = Ka5 A1
53 = 5nno Asa3
58 = Kusumi 58ru
81 = Taka8shi A1
So...to answer
Vikitty...
1444 = Ishiyoshi.