756

756 is a positive integer. In decimal notation it is written as 756. Its prime factorization is 2^2 × 3^3 × 7, which shows that it is even and composite.

756 is a pronic number, equal to 27 × 28. It also equals the binomial coefficient C(28,2) and twice the 27th triangular number (2 × T_27, where T_27 = 27 × 28 / 2 = 378). The number has 24 positive divisors: 1, 2, 3, 4, 6, 7, 9, 12, 14, 18, 21, 27, 28, 36, 42, 54, 63, 84, 108, 126, 189, 252, 378, 756. The sum of all divisors is 2240, so the sum of proper divisors is 1484, making 756 an abundant number.

In other bases, 756 is 1011110100 in binary, 1364 in octal, and 2F4 in hexadecimal. In Roman numerals it is DCCLVI. It is a Harshad number in base 10, since the sum of its digits (7 + 5 + 6) is 18 and 756 ÷ 18 = 42.

Historically, the year 756 CE falls in the early medieval period. Notably, Pepin the Short defeated the Lombards and donated lands to the Pope, establishing the Papal States.