Properties of the Number 20015

Twenty Thousand Fifteen

Basics

Value: 20014 → 20015 → 20016

Parity: odd

Prime: No

Previous Prime: 20011

Next Prime: 20021

Digit Sum: 8

Digital Root: 8

Palindrome: No

Factorization: 5 × 4003

Divisors: 1, 5, 4003, 20015

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2730 Try Today's Challenge

Representations

Binary: 100111000101111

Octal: 47057

Duodecimal: B6BB

Hexadecimal: 4e2f

Square: 400600225

Square Root: 141.4743793059365

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 10·R_k + 3 is prime, where R_k is the repunit (A002275) of length k. A56654

T(n,k)=Number of nXk 0..3 arrays with no element equal to two plus the sum of elements to its left or two plus the sum of the elements above it, modulo 4. A238997

Number of Fermat pseudoprimes to bases 2 and 3 less than 10ⁿ. A114246

Positive integers i for which A112049(i) == 8. A112068

a(n) = ∑_k=1..n k·A088370(n,k). A309371

G.f.: x + x² / ∏_n>=1 (1 - a(n)*xⁿ). A345973

Number of coprime positive integer S-unit solutions to a + b = c where a <= b < c, and where S = {prime(1), ..., prime(n)}. A362593

a(n) = (n+5)³ - n³. A38867

Binomial transform of the "1,2,3,..." triangle. A125027

Number of n X 2 0..3 arrays with no element equal to two plus the sum of elements to its left or two plus the sum of the sum of elements above it, modulo 4. A238991