Properties of the Number 18961

Eighteen Thousand Nine Hundred Sixty-One

Basics

Value: 18960 → 18961 → 18962

Parity: odd

Prime: No

Previous Prime: 18959

Next Prime: 18973

Digit Sum: 25

Digital Root: 7

Palindrome: No

Factorization: 67 × 283

Divisors: 1, 67, 283, 18961

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 100101000010001

Octal: 45021

Duodecimal: AB81

Hexadecimal: 4a11

Square: 359519521

Square Root: 137.69894698217558

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

Numbers k such that k divides 1 plus the sum of the first k primes. A128165

Twice partitioned numbers where the first partition is constant and the latter partitions are strict. A279788

Logarithmic derivative of A112938 such that a(n)=(1/4)*A112938(n+1) for n>0, where A112938 equals the INVERT transform (with offset) of quadruple factorials A008545. A112939

Semiprimes in A003215. A113530

a(n) = 12·n² + 18·n + 7. A154105

Triangle read by rows: T(n,k) is the number of rooted ordered trees with node weights summing to n, where the root has weight 0, all internal nodes have weight 1, and leaf nodes have weights in {1,...,k}. A384685

Gaps of 7 in sequence A038593 (upper terms). A38654

Least number k >= 0 such that (n!+k)/n is prime. A245695

a(n) = binomial(2·n,n) - ceiling(4ⁿ/(2·sqrt(n))). A282710

Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 78 ones. A31846