Properties of the Number 19911

Nineteen Thousand Nine Hundred Eleven

Basics

Value: 19910 → 19911 → 19912

Parity: odd

Prime: No

Previous Prime: 19891

Next Prime: 19913

Digit Sum: 21

Digital Root: 3

Palindrome: No

Factorization: 3 × 6637

Divisors: 1, 3, 6637, 19911

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 100110111000111

Octal: 46707

Duodecimal: B633

Hexadecimal: 4dc7

Square: 396447921

Square Root: 141.10634287656953

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

a(n) = ∑_k=0..n (-1)^n-k*k·Stirling2(n,k). A101851

Number of integer partitions of n whose odd parts are relatively prime. A366850

Numbers using only digits 1 and 9. A284294

Number of partitions of n into an odd number of parts that are not multiples of 3. A339405

Indices of primes in the sequence defined by A(0) = 29, A(n) = 10·A(n-1) - 31 for n > 0. A101963

Number of permutations of length n which avoid the patterns 2134, 3421, 4132. A116833

a(n) = A121295(n) - A121263(n). A131011

Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 547", based on the 5-celled von Neumann neighborhood. A272840

Numbers k with the property that the square root of the product of the digits of k is equal to the sum of the square roots of its digits. A281745

Number of mutual-visibility sets in the n-ladder graph. A389183