Properties of the Number 1280

One Thousand Two Hundred Eighty

Basics

Value: 1279 → 1280 → 1281

Parity: even

Prime: No

Previous Prime: 1279

Next Prime: 1283

Digit Sum: 11

Digital Root: 2

Palindrome: No

Factorization: 2 ⁸ × 5

Divisors: 1, 2, 4, 5, 8, 10, 16, 20, 32, 40

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10100000000

Octal: 2400

Duodecimal: 8A8

Hexadecimal: 500

Square: 1638400

Square Root: 35.77708763999664

Classification

Fibonacci: No

Bell Number: No

Factorial Number: No

Regular Number: Yes

Perfect Number: No

Special

Kaprekar Constant: No

Munchausen Constant: No

Armstrong Number: No

Kaprekar Number: No

Catalan Number: No

Vampire Number: No

Taxicab Number: No

Super Prime: No

Friedman Number: No

Fermat Number: No

Cullen Number: No

OEIS Sequences

Moser-de Bruijn sequence: sums of distinct powers of 4. A695

a(n) = (n+2)*2^n-1. A1792

Triangle of coefficients of Chebyshev's T(n,x) polynomials (powers of·in increasing order). A53120

Number of partitions of n in which the number of parts divides n. A67538

Antisigma(n): Sum of the numbers less than n that do not divide n. A24816

Numbers of the form 2ⁱ*5^j with i, j >= 0. A3592

Expansion of (1+x)/(1-4·x). A3947

Sums of two distinct powers of 2. A18900

a(n) = 5·2ⁿ. A20714

Number of partitions with no even part repeated; partitions of n in which no parts are multiples of 4. A1935