864

864 is the natural number that follows 863 and precedes 865. In prime factorization, 864 = 2^5 × 3^3.

864 has 24 divisors, since (5 + 1)(3 + 1) = 24. It is an even composite number. The sum of its positive divisors is σ(864) = 2520, so the sum of proper divisors is 1656, making 864 an abundant number. It is also a Harshad (Niven) number in base 10, since 8 + 6 + 4 = 18 and 864/18 = 48. With only 2 and 3 as prime factors, 864 is a practical number.

Representations in different bases: in binary 1101100000_2, in octal 1540_8, and in hexadecimal 0x360.

In telecommunications, 864 is the area code for much of western South Carolina, including Greenville and Spartanburg.

Additionally, 864 hours equal 36 days, illustrating a common time conversion.