525

525 is a natural number that follows 524 and precedes 526. In mathematics, it is an odd composite number with prime factorization 3 × 5^2 × 7.

The positive divisors of 525 are 1, 3, 5, 7, 15, 21, 25, 35, 75, 105, 175, and 525, for a total of 12 divisors. Its Euler’s totient value is φ(525) = 240, and the sum of its divisors is σ(525) = 992.

In numeral representations, 525 is written as DXXV in Roman numerals. In binary it is 1000001101, and in base 3 it equals 201110_3. In base 5 it equals 4100_5.

In science and technology, 525 nanometers corresponds to green light in the visible spectrum. In the history of television, 525 lines per frame describes the NTSC standard resolution, with interlaced fields totaling 262.5 lines per field.

As a calendar year, 525 CE appears in historical contexts, marking events of late antiquity depending on regional scholarship.