Properties of the Number -21797

Twenty-One Thousand Seven Hundred Ninety-Seven

Basics

Value: -21798 → -21797 → -21796

Parity: odd

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 26

Digital Root: 8

Palindrome: No

Factorization: 71 × 307

Divisors: 1, 71, 307, 21797

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: -101010100100101

Octal: -52445

Duodecimal: -10745

Hexadecimal: -5525

Square: 475109209

Square Root: 147.63807097087118

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

Numerators of the partial alternating sums of the reciprocals of the alternating sum of divisors function (A206369). A379621

Composite numbers generated by the Euler polynomial x² + x + 41. A145292

T(n,k) = Number of (n+2) X (k+2) 0..3 arrays with every 3 X 3 subblock row and diagonal sum equal to 1 2 4 6 or 7 and every 3 X 3 column and antidiagonal sum not equal to 1 2 4 6 or 7. A252558

Semiprimes generated by the Euler polynomial x² + x + 41. A228183

MM-numbers of crossing, capturing multiset partitions (with empty parts allowed). A326259

Positions of 0's in A330314. A330325

Expansion of (1-x)/(1 - x - x³ - 2·x⁴ + 2·x⁵). A52914

Numbers n such that σ (φ ( n ) ) = σ (σ (n ) ) where φ is Euler's totient and σ is the multiplicative sum-of-divisors function. A65556

a(n) = (2^p - p² - 1)/6 where p = prime(n). A166743

Number of (n+2)X(6+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 1 2 4 6 or 7 and every 3X3 column and antidiagonal sum not equal to 1 2 4 6 or 7. A252556