Properties of the Number 18621

Eighteen Thousand Six Hundred Twenty-One

Basics

Value: 18620 → 18621 → 18622

Parity: odd

Prime: No

Previous Prime: 18617

Next Prime: 18637

Digit Sum: 18

Digital Root: 9

Palindrome: No

Factorization: 3 ² × 2069

Divisors: 1, 3, 9, 2069, 6207, 18621

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 100100010111101

Octal: 44275

Duodecimal: A939

Hexadecimal: 48bd

Square: 346741641

Square Root: 136.4587849865299

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 3 X n binary arrays with a path of adjacent 1's from top row to bottom row. A69361

Array read by antidiagonals: T(m,n) is the number of m X n binary arrays with a path of adjacent 1's from top row to bottom row. A359576

Number of ways to write n as an ordered sum of 9 nonprime numbers. A341486

Odd composites k such that σ(k) has the same powerful part as k, where σ is the sum of divisors function. A386425

Number of n X 5 binary arrays with a path of adjacent 1's from top row to bottom row. A69380

Numbers with 3 or more prime factors (with multiplicity) such that every concatenation of their prime factors is prime. A217264

Terms k of A228058 such that gcd(k - A048250(k), A162296(k) - k) = A162296(k) - k. A325376

Indices m such that A128646(m)-1 is prime, where A128646 = denominator of partial sums of 1/(p(i)-1). A137689

Replacing each digit d in decimal expansion of n with d² yields a prime at each step when done recursively three times. A316604

Expansion of 1/(1-x³-x⁴-x⁵-x⁶-x⁷-x⁸-x⁹). A17822