1613
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 11
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 1614
- Proper Divisor Sum (Aliquot Sum)
- 1
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 1612
- Möbius Function
- -1
- Radical
- 1613
- 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
- 21
- 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
- 255
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Largest prime factor of 2^n + 1.at n=26A002587
- a(n) = 1000*log_10(n) rounded to the nearest integer.at n=40A004226
- Smallest number that requires n iterations of the bi-unitary totient function (A116550) to reach 1.at n=30A005424
- 1 + (sum of first n odd primes - n)/2.at n=40A005521
- From relations between Siegel theta series.at n=12A006476
- Numbers k such that k-6, k, and k+6 are primes.at n=41A006489
- Coordination sequence T1 for Zeolite Code EMT.at n=33A008086
- Numbers k such that the continued fraction for sqrt(k) has period 3.at n=9A013643
- Numbers k such that the k-th Euclid number A006862(k) = 1 + (Product of first k primes) is prime.at n=15A014545
- Primes p such that 7*p + 8 is also prime.at n=46A023226
- Numbers that are the sum of 3 nonzero squares in exactly 10 ways.at n=35A025330
- Numbers that are the sum of 3 distinct nonzero squares in exactly 10 ways.at n=35A025348
- Index of 10^n within the sequence of the numbers of the form 8^i*10^j.at n=53A025746
- Primes with even number of 1's in binary expansion such that next prime also has even number of 1's.at n=39A027701
- Smallest nontrivial extension of n-th palindrome which is a prime.at n=24A030675
- a(n) = prime(8*n - 1).at n=31A031374
- a(n) = prime(6*n-3).at n=42A031387
- a(n) = prime(7*n - 4).at n=36A031394
- Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted then there are a pair of central terms both equal to 6.at n=5A031419
- Least term in period of continued fraction for sqrt(n) is 6.at n=14A031430