Properties of the Number 31820

Thirty-One Thousand Eight Hundred Twenty

Basics

Value: 31819 → 31820 → 31821

Parity: even

Prime: No

Previous Prime: 31817

Next Prime: 31847

Digit Sum: 14

Digital Root: 5

Palindrome: No

Factorization: 2 ² × 5 × 37 × 43

Divisors: 1, 2, 4, 5, 10, 20, 37, 43, 74, 86

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 111110001001100

Octal: 76114

Duodecimal: 164B8

Hexadecimal: 7c4c

Square: 1012512400

Square Root: 178.38161340227865

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 integer partitions of n such that either the run-lengths or the negated run-lengths are unimodal. A332746

Numerators of continued fraction convergents to sqrt(397). A41754

Number of 5-gonal compositions of n into positive parts. A69983

Number of ordered triples (w,x,y) with all terms in {-n,...-1,1,...,n} and w+4x+4y>0. A211626

Number of ordered triples (w,x,y) with all terms in {-n, ..., -1, 1, ..., n} and 4w + x + y > 0. A211629

Triangle of numbers read by rows: T(n,k) = ∑_i=0..n binomial(n,i)*(n-i)!*Stirling1(i,k)*TC(n,i) where TC(n,k) = ∑_i=0..n-k binomial(n+1,n-k-i)*Stirling2(i+3,i+1)*(-1)ⁱ for n >= 0, 0 <= k <= n. A370518

Average of 4 primes where the integer Schwarzian derivative is zero. A94903

a(n) = ∑_{-n<i<n, -n<j<n, gcd{i,j}=3} (n-|i|)*(n-|j|). A331774

Irregular table read by rows: T(n,k) is the number of k-sided polygons, for k>=3, in a square when straight line segments connect the n-1 points between each corner that divide each edge into n equal parts to the n-1 points on the edge on the opposite side of the square. A355801

Biperiod squares: square numbers whose digits repeat twice in order. A92118