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Properties of the Number 19865

Nineteen Thousand Eight Hundred Sixty-Five

Basics

Value: 19864 → 19865 → 19866

Parity: odd

Prime: No

Previous Prime: 19861

Next Prime: 19867

Digit Sum: 29

Digital Root: 2

Palindrome: No

Factorization: 5 × 29 × 137

Divisors: 1, 5, 29, 137, 145, 685, 3973, 19865

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 100110110011001

Octal: 46631

Duodecimal: B5B5

Hexadecimal: 4d99

Square: 394618225

Square Root: 140.9432509913121

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

Array read by rows: T(n,k) is the number of nonisomorphic n X n matrices with nonnegative integer entries and row sums k under row and column permutations, (n >= 1, k >= 0). A318951
Number of 4 X 4 matrices with nonnegative integer entries and all row sums equal to n, up to row and column permutation. A58390
a(1) = 1, then multiply, subtract, and add 2, 3, 4; 5, 6, 7; ... in that order. A362272
Numbers m such that Stern polynomial B(m,x) has no irreducible polynomial factors that themselves are Stern polynomials. The initial a(1) = 1 is included by convention. A389918
Number of 6 X 6 binary matrices with n=0...36 ones up to row and column permutations. A52370
Non-isomorphic proper colorings of the 3 X 3 grid graph using at most n colors under rotational and reflectional symmetries. A321244
Odd numbers of the form k·reverse(k) (where reverse(k) is the binary reversal of k, A030101(k)). A331587
Number of subsets of { 1, ..., n } containing an arithmetic progression of length 4. A18789
Quasi-Carmichael numbers to base -7: squarefree composites n such that prime p∣n ==> p+7∣n+7. A29567
a(n) is the smallest k such that number of non-unitary prime divisors of central binomial coefficient, A000984(k) = C(2·k,k) equals n. A81393