15307
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 15308
- Proper Divisor Sum (Aliquot Sum)
- 1
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 15306
- Möbius Function
- -1
- Radical
- 15307
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- no
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- no
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 84
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1788
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Discriminants of imaginary quadratic fields with class number 23 (negated).at n=31A046020
- a(n) is the n-th prime = -1 (mod n).at n=42A093871
- Total sum of parts of multiplicity 2 in all partitions of n.at n=30A117525
- Records in A117677.at n=44A117679
- Primes for which the weight as defined in A117078 is 11 and the gap as defined in A001223 is 6.at n=32A119597
- Primes congruent to 32 mod 47.at n=36A142383
- Primes congruent to 43 mod 53.at n=33A142573
- Primes congruent to 26 mod 59.at n=25A142753
- Primes congruent to 57 mod 61.at n=29A142855
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 1, 1), (0, 0, -1), (1, -1, 1), (1, 1, 0)}.at n=8A149387
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, 0, 1), (0, 1, -1), (0, 1, 1), (1, -1, 1), (1, 1, 0)}.at n=7A150881
- Primes p of the form 4m+3 for which there are exactly as many primitive roots modulo p in the interval [0,p/2] as in the interval [p/2,p].at n=23A172490
- Smallest emirp corresponding to A178585.at n=21A178586
- The smaller member prime(i) of an emirp pair (prime(i),prime(j)), such that the digit sum of i equals the digit sum of j.at n=14A178613
- Ninth prime p such that (p+n)^2+n is prime but (p+j)^2+j is not prime for all 0<j<n.at n=19A238681
- Number of length 4+2 0..n arrays with every three consecutive terms having the sum of some two elements equal to twice the third.at n=31A248437
- a(n) = core(Sum_{i=0,...,n} core(binomial(n,i))), where core(n) = A007913(n).at n=19A249416
- Number of (n+1) X (5+1) 0..2 arrays with every 2 X 2 subblock summing to 4 and no 2 X 2 subblock having exactly two nonzero entries.at n=9A251146
- Number of length-n 0..6 arrays with no repeated value differing from the previous repeated value by other than plus two or minus 1.at n=4A269638
- T(n,k)=Number of length-n 0..k arrays with no repeated value differing from the previous repeated value by other than plus two or minus 1.at n=49A269640