16693
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 16694
- 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
- 16692
- Möbius Function
- -1
- Radical
- 16693
- 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
- 128
- 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
- yes
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1931
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- a(n) = M(n) + m(n) for n >= 2, where M(n) = max{ a(i) + a(n-i): i = 1..n-1 }, m(n) = min{ a(i) + a(n-i): i = 1..n-1 }.at n=30A022905
- Numbers whose base-4 representation contains exactly three 0's and four 1's.at n=33A045032
- Numbers k such that 231*2^k-1 is prime.at n=47A050867
- Numbers k such that k^4 == 1 (mod 5^5).at n=21A056102
- Twin-prime-indexed primes (TWIPS): members of a pair of twin primes whose prime index is also a member of a pair of twin primes.at n=35A087373
- Primes p such that the sum of the digits of p is not prime, but the sum of the squares of the digits of p is prime.at n=27A091362
- Terms in A006512 containing the digit "6" at least once, such that changing every "6" to a "9" and vice versa yields a larger term in A006512.at n=6A123211
- Primes congruent to 51 mod 53.at n=38A142581
- Primes congruent to 55 mod 59.at n=33A142782
- Primes congruent to 40 mod 61.at n=32A142838
- Primes in toothpick sequence A153006.at n=23A153009
- Primes of the form 2*n^2 + 22*n + 9.at n=12A154601
- a(n) = (a(n-1)^2 + a(n-2)^2 + a(n-1)*a(n-2))/a(n-3) with three initial ones.at n=6A165903
- Primes p such that p^s ends with p, where s is sum of the digits of p.at n=8A171267
- Primes p that p//13 and p//31 are consecutive primes.at n=24A176601
- Number of nX4 0..3 arrays with every row and column nondecreasing rightwards and downwards, and the number of instances of each value within one of each other.at n=9A201447
- Numbers n such that n^2 + 1 is divisible by a 5th power.at n=10A218564
- Numbers k such that k^2 + 1 is divisible by a 6th power.at n=2A218565
- Primes p such that if q is the next prime after p then the concatenation of p with q and the concatenation of q with p are both primes.at n=30A225575
- Number of n X 7 0..1 arrays with no element equal to more than one of its horizontal and vertical neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.at n=12A280439