Properties of the Number 1729

One Thousand Seven Hundred Twenty-Nine

Basics

Value: 1728 → 1729 → 1730

Parity: odd

Prime: No

Previous Prime: 1723

Next Prime: 1733

Digit Sum: 19

Digital Root: 1

Palindrome: No

Factorization: 7 × 13 × 19

Divisors: 1, 7, 13, 19, 91, 133, 247, 1729

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 11011000001

Octal: 3301

Duodecimal: 1001

Hexadecimal: 6c1

Square: 2989441

Square Root: 41.58124577258358

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: Yes

Super Prime: No

Friedman Number: No

Fermat Number: No

Cullen Number: No

OEIS Sequences

Fermat pseudoprimes to base 2, also called Sarrus numbers or Poulet numbers. A1567

Carmichael numbers: composite numbers k such that a^k-1 == 1 (mod k) for every a coprime to k. A2997

Taxi-cab numbers: sums of 2 cubes in more than 1 way. A1235

Centered cube numbers: n³ + (n+1)³. A5898

Expansion of 1/((1-x)⁴*(1+x)). A2623

Generalized heptagonal numbers: m*(5·m - 3)/2, m = 0, +-1, +-2 +-3, ... A85787

Sextuple factorials, 6-factorials, n!!!!!!, n!6. A85158

3-Carmichael numbers: Carmichael numbers equal to the product of 3 primes: k = p·q*r, where p < q < r are primes such that a^k-1 == 1 (mod k) if a is prime to k. A87788

a(n) = ∑_d∣n (-1)^d-1*d². A321543

Sum of divisors of square numbers. A65764