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Properties of the Number 21070

Twenty-One Thousand Seventy

Basics

Value: 21069 → 21070 → 21071

Parity: even

Prime: No

Previous Prime: 21067

Next Prime: 21089

Digit Sum: 10

Digital Root: 1

Palindrome: No

Factorization: 2 × 5 × 7 2 × 43

Divisors: 1, 2, 5, 7, 10, 14, 35, 43, 49, 70

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101001001001110

Octal: 51116

Duodecimal: 1023A

Hexadecimal: 524e

Square: 443944900

Square Root: 145.15508947329405

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

Graham-Sloane-type lower bound on the size of a ternary (n,3,4) constant-weight code. A30504
7 times heptagonal numbers: a(n) = 7·n*(5·n-3)/2. A152777
Number of partitions of n, where the difference between the number of odd parts and the number of even parts is 8. A240017
a(n) = Fibonacci(n) + n·Lucas(n). A258321
Number of partitions of n into colored blocks of equal parts, such that all colors from a set of size seven are used and the colors are introduced in increasing order. A327290
Triangle read by rows: row n gives coefficients T(n,k), in descending powers of m, of a polynomial Qn(m) (of degree n - 1) in an expression for the number of subdivisions A(m,n) of a grid with two rows. A336244
a(n) is the least integer k such that σ(k)/(d(k)*sopf(k)) = n where d=A000005, σ=A000203 and sopf=A008472. A328174
Square array read by antidiagonals: A(n,k) is the number of ordered solutions (x1, x2, ..., xn) to equation φ(∏i=1..n xi) = k * ∑i=1..n φ(xi), or -1 if there are infinitely many solutions, n >= 1, k >= 1. A336710
a(n) is the smallest number k larger than a(n-1) such that n·d(k)*sopf(k)=σ(k), where d is the number of divisors (A000005) and sopf the sum of prime factors without repetition (A008472). A134382
Number of rooted non-separable bi-Eulerian planar maps with 2n edges. Bi-Eulerian means all its vertices and faces are of even valency. A69729