Properties of the Number 31439

Thirty-One Thousand Four Hundred Thirty-Nine

Basics

Value: 31438 → 31439 → 31440

Parity: odd

Prime: No

Previous Prime: 31397

Next Prime: 31469

Digit Sum: 20

Digital Root: 2

Palindrome: No

Factorization: 149 × 211

Divisors: 1, 149, 211, 31439

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 111101011001111

Octal: 75317

Duodecimal: 1623B

Hexadecimal: 7acf

Square: 988410721

Square Root: 177.31046218427159

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 n such that the digits of σ(n) are exactly the same (albeit in different order) as the digits of φ(n), in base 10. A175795

Expansion of g.f.: (1-2·x-sqrt(1-4·x+8·x³-4·x⁴))/(2·x²*(1-x)). A135052

Number of compositions of n in which the greatest part is even. A103422

Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 39 ones. A31807

Brilliant numbers k such that 2k+1 is also brilliant. A85649

Indices of primes in sequence defined by A(0) = 83, A(n) = 10·A(n-1) + 63 for n > 0. A101079

Indices of primes in the sequence defined by A(0) = 29, A(n) = 10·A(n-1) - 21 for n > 0. A101965

Number of (n+4) X 9 0..1 matrices with each 5 X 5 subblock idempotent. A224687

Number of length n 0..3 arrays with new values introduced in order from both ends. A245158

Numbers n such that n and its reversal are distinct brilliant numbers (A078972). A97435