190 (number)

From Wikipedia, the free encyclopedia
← 189 190 191 →
Cardinalone hundred ninety
Ordinal190th
(one hundred ninetieth)
Factorization2 × 5 × 19
Greek numeralΡϞ´
Roman numeralCXC
Binary101111102
Ternary210013
Senary5146
Octal2768
Duodecimal13A12
HexadecimalBE16

190 (one hundred [and] ninety) is the natural number following 189 and preceding 191.

In mathematics[edit]

190 is a triangular number, a hexagonal number, and a centered nonagonal number, the fourth figurate number (after 1, 28, and 91) with that combination of properties.[1] It is also a truncated square pyramid number.[2]

Integers from 191 to 199[edit]

191
191 is a prime number.
192
192 = 26 × 3 is a 3-smooth number, the smallest number with 14 divisors.
193
193 is a prime number.
194
194 = 2 × 97 is a Markov number, the smallest number written as the sum of three squares in five ways, and the number of irreducible representations of the Monster group.
195
195 = 3 × 5 × 13 is the smallest number expressed as a sum of distinct squares in 16 different ways.
196
196 = 22 × 72 is a square number.
197
197 is a prime number and a Schröder–Hipparchus number.
198
198 = 2 × 32 × 11 is the smallest number written as the sum of four squares in ten ways.
No integer factorial ever ends in exactly 198 zeroes in base 10 or in base 12.[3][4]
There are 198 ridges on a U.S. dollar coin.[5]
199
199 is a prime number and a centered triangular number.

In other fields[edit]

See also[edit]

References[edit]

  1. ^ Sloane, N. J. A. (ed.), "Sequence A272399 (The intersection of hexagonal numbers (A000384) and centered 9-gonal numbers (A060544))", The On-Line Encyclopedia of Integer Sequences, OEIS Foundation
  2. ^ Sloane, N. J. A. (ed.), "Sequence A050409 (Truncated square pyramid numbers: a(n) = Sum_{k = n..2*n} k^2)", The On-Line Encyclopedia of Integer Sequences, OEIS Foundation
  3. ^ "A000966 - OEIS". oeis.org. Retrieved 2022-08-24.
  4. ^ "A136772 - OEIS". oeis.org. Retrieved 2022-08-24.
  5. ^ "Why Do Coins Have Ridges? | Mental Floss". 2022-08-18. Archived from the original on 2022-08-18. Retrieved 2022-08-24.