127

127 < 126 | 128 >
All Numbers
100	101	102	103	104	105	106	107	108	109
110	111	112	113	114	115	116	117	118	119
120	121	122	123	124	125	126	127	128	129
130	131	132	133	134	135	136	137	138	139
140	141	142	143	144	145	146	147	148	149
150	151	152	153	154	155	156	157	158	159
160	161	162	163	164	165	166	167	168	169
170	171	172	173	174	175	176	177	178	179
180	181	182	183	184	185	186	187	188	189
190	191	192	193	194	195	196	197	198	199

127 is the number following 126 and preceding 128.

Properties

• It is the 31st prime number.
• 127 is an odd number.
• 127 is an unhappy number.
  

• 127 is a centered hexagonal number.
  
• 127 is a Mersenne number; it is equal to \(2^{ 7}-1\).
  
• 127 is deficient.
• The 4th Mersenne prime 127 is equal to \(2^{2^3-1}-1\). It is also a Catalan-Mersenne number.In many progamming languages it is the maximum value of an 8-bit signed integer.

Approximations

Notation	Lower bound	Upper bound
Up-arrow notation	5 ↑ 3
Scientific notation	\(1.27\times10^2\)	\(1.271\times10^2\)
Slow-growing hierarchy	\(g_{\omega^{\omega}}(3)\)	\(g_{\omega^{\omega}}(4)\)
Copy notation	1[3]	2[3]
Chained arrow notation	5 → 3
Bowers' Exploding Array Function/Bird's array notation	{5,3}
Fast-growing hierarchy	f1(62)	f1(63)
Hardy hierarchy	Hω(63)	Hω(64)
Middle-growing hierarchy	m(ω,6)	m(ω,7)
Hyper-E notation	E2.1038
Hyper-E notation (non-10 base)	\(E[5]3\)
Hyperfactorial array notation	5!	6!
X-Sequence Hyper-Exponential Notation	5{1}3
Steinhaus-Moser Notation	3[3]	4[3]
PlantStar's Debut Notation	[1]	[2]
H* function	H(-0.3)	H(-0.2)
Bashicu matrix system with respect to version 4	(0)[11]	(0)[12]