Properties of the Number 309

Three Hundred Nine

Basics

Value: 308 → 309 → 310

Parity: odd

Prime: No

Previous Prime: 307

Next Prime: 311

Digit Sum: 12

Digital Root: 3

Palindrome: No

Factorization: 3 × 103

Divisors: 1, 3, 103, 309

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 100110101

Octal: 465

Duodecimal: 219

Hexadecimal: 135

Square: 95481

Square Root: 17.578395831246947

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 k such that (35·10^k - 11)/3 is prime. A268448

Triangle read by rows: T(n,k) is number of partitions of n having k distinct parts (n>=1, k>=1). A116608

Number of primes <= 2ⁿ. A7053

a(n) = n·a(n-1) + (n-1)*a(n-2), a(0) = 1, a(1) = 1. A255

Antisigma(n): Sum of the numbers less than n that do not divide n. A24816

Ulam numbers: a(1) = 1; a(2) = 2; for n>2, a(n) = least number > a(n-1) which is a unique sum of two distinct earlier terms. A2858

Number of fractions in Farey series of order n. A5728

a(n) = 6·n+3. A16945

Centered icosahedral (or cuboctahedral) numbers, also crystal ball sequence for f.c.c. lattice. A5902

Total number of odd entries in first n rows of Pascal's triangle: a(0) = 0, a(1) = 1, a(2k) = 3·a(k), a(2k+1) = 2·a(k) + a(k+1). a(n) = ∑_i=0..n-1 2^wt(i). A6046