Properties of the Number 7978

Seven Thousand Nine Hundred Seventy-Eight

Basics

Value: 7977 → 7978 → 7979

Parity: even

Prime: No

Previous Prime: 7963

Next Prime: 7993

Digit Sum: 31

Digital Root: 4

Palindrome: No

Factorization: 2 × 3989

Divisors: 1, 2, 3989, 7978

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 1111100101010

Octal: 17452

Duodecimal: 474A

Hexadecimal: 1f2a

Square: 63648484

Square Root: 89.31965069345043

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

Triangle T(n,k) of numbers of minimal 5-covers of an unlabeled n+5-set that cover k points of that set uniquely (k=5,..,n+5). A57968

Smallest k such that k·2*p(n)²-1=q is prime, k·2*q²-1=r, k·2*r²-1=s, k·2*r²-1=t, r, s, and t are also prime. A224492

Number of 1 X (n+1) 0..1 arrays with every row least squares fitting to a positive-slope straight line and every column least squares fitting to a zero- or positive-slope straight line, with a single point array taken as having zero slope. A222970

Numbers whose smallest decimal digit is 7. A284068

Increasing gaps among twin primes: size. A36063

Number of 3-separable partitions of n; see Comments. A239469

The number of lit cells in weakly decreasing partitions of n when light shines from the north west. Here partitions are represented from left to right by columns of cells. A366157

Numerators of continued fraction convergents to sqrt(181). A41334

Similar to A072921 but starting with 2. A152231

Expansion of g.f. x*(x-1)*(x+1)³/((2·x³+x²-1)*(x⁴+1)). A107853