Properties of the Number -1381

Three Hundred Eighty-One

Basics

Value: -1382 → -1381 → -1380

Parity: odd

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 13

Digital Root: 4

Palindrome: No

Factorization: 1381

Divisors: 1, 1381

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: -10101100101

Octal: -2545

Duodecimal: -971

Hexadecimal: -565

Square: 1907161

Square Root: 37.16180835212409

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

Corresponds to m = 5 in a family of 4th-order linear recurrence sequences given by a(m,n) = m⁴*a(n-4) + (2·m)²*a(n-3) - 4·a(m-1), a(m,0) = -1, a(m,1) = 4, a(m,2) = -13 + 6*(m-1) + 3*(m-1)², a(m,3) = (-8+m²)². A113251

Numerators of coefficients of an expansion of the logarithm of the Catalan numbers. A220422

a(n) = n² - 917·n + 9479. A161726

Primes p such that (p+1)/2 is prime. A5383

Number of "ON" cells at n-th stage in the "Ulam-Warburton" two-dimensional cellular automaton. A147562

Centered pentagonal numbers: (5n²+5n+2)/2; crystal ball sequence for 3.3.3.4.4. planar net. A5891

Y-toothpick sequence (see Comments lines for definition). A160120

Primes such that their decimal representations interpreted in base 11 are also prime. A91924

Primes of the form 2·k² + 29. A7641

Primes congruent to 1 or 19 (mod 30). A33212