16987
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 31
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 16988
- 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
- 16986
- Möbius Function
- -1
- Radical
- 16987
- 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
- 110
- 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
- 1959
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Primes whose reversal is a square.at n=16A007488
- Number of partitions in parts not of the form 13k, 13k+1 or 13k-1. Also number of partitions with no part of size 1 and differences between parts at distance 5 are greater than 1.at n=48A035949
- Primes p from A031924 such that A052180(primepi(p)) = 13.at n=29A052233
- Prime number spiral (clockwise, South spoke).at n=22A054566
- Sequence of prime numbers whose reverse is a nontrivial prime power (A025475).at n=12A067194
- Primes whose digit reversal is a nontrivial power.at n=19A069798
- Primes with digit sum = 31.at n=20A106767
- Expansion of 1/sqrt(1-2x-5x^2-6x^3+9x^4).at n=9A108489
- Prime numbers whose digit reversal is a powerful(1) number (A001694).at n=24A115685
- Same as A007488, but with the numbers arranged so that their reversals are in increasing order.at n=23A132388
- Least prime, p, such that p mod (sum of the digits of p) = n.at n=30A138792
- Concatenation of n and n-th Fibonacci number.at n=15A139113
- Primes congruent to 27 mod 53.at n=34A142557
- Primes congruent to 54 mod 59.at n=34A142781
- Primes congruent to 29 mod 61.at n=38A142827
- Primes p such that continued fraction of (1 + sqrt(p))/2 has period 6: primes in A146331.at n=20A146351
- Primes of the form 9*k^2-10*k+3.at n=11A154261
- a(n) = 9*n^2 - 10*n + 3.at n=44A154262
- Greater of two consecutive primes, p < q, such that both p*q+p-q and p*q-p+q are prime numbers.at n=24A154552
- Primes p0 such that p0+p1+p2-+2 are primes; p0,p1,p2 are three consecutive primes.at n=19A158351