Properties of the Number 21399

Twenty-One Thousand Three Hundred Ninety-Nine

Basics

Value: 21398 → 21399 → 21400

Parity: odd

Prime: No

Previous Prime: 21397

Next Prime: 21401

Digit Sum: 24

Digital Root: 6

Palindrome: No

Factorization: 3 × 7 × 1019

Divisors: 1, 3, 7, 21, 1019, 3057, 7133, 21399

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101001110010111

Octal: 51627

Duodecimal: 10473

Hexadecimal: 5397

Square: 457917201

Square Root: 146.28397041371278

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

Number of combinatorial configurations of type (n₃). A1403

a(n) = (A002704(n) - 2)/2. A262584

Numerators of continued fraction convergents to sqrt(92). A41164

a(n) = 27·n²/2 + 45·n/2 - 12 (n>=1). A304375

Number of walks within N³ (the first octant of Z³) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 1, 0), (0, 1, -1), (1, -1, 1), (1, 0, 0)}. A148250

Numbers k such that k^{k + 1} == k + 1 (mod 2·k + 1) while 2·k+1 is not prime. A380831

Number of paths from (0,0) to (3n,0) that stay in the first quadrant (but may touch the horizontal axis), consisting of steps u=(2,1),U=(1,2), or d=(1,-1) and have no hills (a hill is either a ud or a Udd starting at the x-axis). A108432

Decimal expansion of 1/395. A21399