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Properties of the Number 28121

Twenty-Eight Thousand One Hundred Twenty-One

Basics

Value: 28120 → 28121 → 28122

Parity: odd

Prime: No

Previous Prime: 28111

Next Prime: 28123

Digit Sum: 14

Digital Root: 5

Palindrome: No

Factorization: 61 × 461

Divisors: 1, 61, 461, 28121

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 110110111011001

Octal: 66731

Duodecimal: 14335

Hexadecimal: 6dd9

Square: 790790641

Square Root: 167.69317219254933

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 40-gonal numbers. A195317
Positive numbers y such that y2 is of the form x2+(x+89)2 with integer x. A160055
Numerators of continued fraction convergents to sqrt(692). A42330
Hypotenuses of primitive Pythagorean triples in A195532 and A195533. A195534
Odd composite integers m such that A000032(3·m-J(m,5)) == 3·J(m,5) (mod m), where J(m,5) is the Jacobi symbol. A339724
Number of different figures obtained by a putting two Young diagrams of partitions λ and μ, such that |λ| + |μ| = n on top of each other. A225751
Number of length 3 1..(n+2) arrays with no leading partial sum equal to a prime and no consecutive values equal. A255718
Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 521", based on the 5-celled von Neumann neighborhood. A272736
a(n) is obtained by starting with 1, sequentially concatenating all decimal numbers up to n, and then, starting from n-1, sequentially concatenating all decimal numbers down to 1. A173426
a(n) = the smallest prime divisor of A173426(n) = concatenation of (1, 2, 3,..., n, n-1, ..., 1) for n > 1; a(1) = 1. A75023