Properties of the Number 18690

Eighteen Thousand Six Hundred Ninety

Basics

Value: 18689 → 18690 → 18691

Parity: even

Prime: No

Previous Prime: 18679

Next Prime: 18691

Digit Sum: 24

Digital Root: 6

Palindrome: No

Factorization: 2 × 3 × 5 × 7 × 89

Divisors: 1, 2, 3, 5, 6, 7, 10, 14, 15, 21

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 100100100000010

Octal: 44402

Duodecimal: A996

Hexadecimal: 4902

Square: 349316100

Square Root: 136.71137480107498

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

G.f. A(x) satisfies: the sum of the coefficients of x^k, k=0..n, in A(x)ⁿ equals (3·n)!/n!³, which is de Bruijn's sequence S(3,n) (A006480), for n>=0. A232683

Irregular triangle read by rows T(n,k) (n>=1, 0<=k<=n(n-1)/2) giving the total number of connected components in all subgraphs (V,E') with |E'|=k of the complete labeled graph K_n=(V,E). A125205

Numbers n for which 2 < A257993(A276086(A276086(n))) < A257993(n), where A276086 converts the primorial base expansion of n into its prime product form, and A257993 returns the index of the least prime not present in its argument. A328762

Composite numbers with properties that its digits (which may appear with multiplicity) may not appear in any of its factors (wherein the digits may also appear with multiplicity) and the combined digits of the product and the factors must have at least one of each of the ten digits. A370972

Records for unitary abundant numbers, i.e., those integers which set a record for having a greater unitary abundance than any of their predecessors. A129499

a(n) = ∑_{k=0..floor((n-1)/3)} 2^k * |Stirling1(n,3·k+1)|. A357832

Record values in A106530. A106531

Numbers k such that 2·k-1, 4·k-1, 6·k-1 and 8·k-1 are primes. A124487

Positions of 0's in A330314. A330325

Triangle read by rows: T(n,k) is the number of nested cycle partitions of n labeled nodes into k components. A392471