Properties of the Number 64721

Sixty-Four Thousand Seven Hundred Twenty-One

Basics

Value: 64720 → 64721 → 64722

Parity: odd

Prime: No

Previous Prime: 64717

Next Prime: 64747

Digit Sum: 20

Digital Root: 2

Palindrome: No

Factorization: 61 × 1061

Divisors: 1, 61, 1061, 64721

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 1111110011010001

Octal: 176321

Duodecimal: 31555

Hexadecimal: fcd1

Square: 4188807841

Square Root: 254.40322325002094

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

Composite and every divisor (except 1) contains the digit 6. A62674

T(n,k)=Number of nXk 0..3 arrays with no element equal to zero plus the sum of elements to its left or one plus the sum of the elements above it or one plus the sum of the elements diagonally to its northwest, modulo 4. A240271

E.g.f. satisfies A(x) = exp( x * ( exp(x) * A(x) )² ). A360547

Numbers m such that the sum of the first k odd primes = m-th odd prime. A179321

Numbers n such that n = π(n)*k + 1 for some k. A65136

Numbers n such that there exists at least one number j and π(m) = d₁ d₂ ... d_j*d_j+1 d_j+2 ... d_k where d₁ d₂ ...d_k is the decimal expansion of n. A112012

Number of n X 6 0..3 arrays with no element equal to zero plus the sum of elements to its left or one plus the sum of elements above it or one plus the sum of the elements diagonally to its northwest, modulo 4. A240270

Number of 3Xn 0..3 arrays with no element equal to zero plus the sum of elements to its left or one plus the sum of the elements above it or one plus the sum of the elements diagonally to its northwest, modulo 4. A240273

Coefficient of·in the reduction by x²->x+1 of the polynomial p(n,x) defined at Comments. A193041

Numbers n such that 5ⁿ-4^n-1 is prime. A272296