SELECT count(*) NoOfColumns FROM SYSCOLUMNS
WHERE id= (Select id from SYSOBJECTS where name = 'TableName')

--FOR Given Table Name.
SELECT COUNT(*) FROM SYS.COLUMNS
WHERE ID = OBJECT_ID('<TABLENAME>')

--For All UD Tables in the current DB
SELECT OBJ.NAME,COUNT(*) 
FROM SYS.COLUMNS COL,SYS.OBJECTS OBJ
WHERE OBJ.OBJECT_iD = COL.OBJECT_ID
AND TYPE = 'U'
GROUP BY OBJ.NAME

Select Count(Column_Name) As NoOfColumns From 
Information_Schema.Columns Where table_Name='Company'

SELECT count(*) NoOfColumns FROM SYSCOLUMNS
WHERE id= (Select id from SYSOBJECTS where name 
= 'TableName')

SELECT DISTINCT SYS.NAME,COUNT(*) FROM SYSOBJECTS SYS
INNER JOIN SYSCOLUMNS SYSCOL ON SYSCOL.ID=SYS.ID
WHERE SYS.XTYPE='U' GROUP BY SYS.NAME

sp_help tablename

  another command is

     select name from syscolumns where id=object_id
('table_name')

SELECT
K_Table = FK.TABLE_NAME,
FK_Column = CU.COLUMN_NAME,
PK_Table = PK.TABLE_NAME,
PK_Column = PT.COLUMN_NAME,
Constraint_Name = C.CONSTRAINT_NAME
FROM INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS C
INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS FK ON
C.CONSTRAINT_NAME = FK.CONSTRAINT_NAME
INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS PK ON
C.UNIQUE_CONSTRAINT_NAME = PK.CONSTRAINT_NAME
INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE CU ON
C.CONSTRAINT_NAME = CU.CONSTRAINT_NAME
INNER JOIN (
SELECT i1.TABLE_NAME, i2.COLUMN_NAME
FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS i1
INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE i2 ON
i1.CONSTRAINT_NAME = i2.CONSTRAINT_NAME
WHERE i1.CONSTRAINT_TYPE = 'PRIMARY KEY'
) PT ON PT.TABLE_NAME = PK.TABLE_NAME