Properties of the Number 1405

One Thousand Four Hundred Five

Basics

Value: 1404 → 1405 → 1406

Parity: odd

Prime: No

Previous Prime: 1399

Next Prime: 1409

Digit Sum: 10

Digital Root: 1

Palindrome: No

Factorization: 5 × 281

Divisors: 1, 5, 281, 1405

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10101111101

Octal: 2575

Duodecimal: 991

Hexadecimal: 57d

Square: 1974025

Square Root: 37.48332962798263

Classification

Fibonacci: No

Bell Number: No

Factorial Number: No

Regular Number: No

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

Centered square numbers: a(n) = 2·n*(n+1)+1. Sums of two consecutive squares. Also, consider all Pythagorean triples (X, Y, Z=Y+1) ordered by increasing Z; then sequence gives Z values. A1844

a(n) = n + (n+1)². A28387

a(n) = ceiling(n²/2). A982

Table by antidiagonals of T(n,k) = n·T(n,k-1) + T(n,k-2) starting with T(n,1) = 1. A73133

Square array, read by antidiagonals, where row n equals the crystal ball sequence for the A_n lattice. A108625

Array A(n,k) = n·A(n,k-1) + A(n,k-2) read by upward antidiagonals, starting A(n,0) = 0, A(n,1) = 1. A172236

Array read by ascending antidiagonals. A(n, k) = Fibonacci(k, n), where Fibonacci(n, x) are the Fibonacci polynomials. A352361

Denominators of continued fraction convergents to sqrt(10). A5668

Array A(n, k) = Fibonacci(n+1, k), with A(n, 0) = A(n, n) = 1, read by antidiagonals. A157103

Moebius transform of A064987, n*σ(n). A69097