6158
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 9240
- Proper Divisor Sum (Aliquot Sum)
- 3082
- 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
- 3078
- Möbius Function
- 1
- Radical
- 6158
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- 155
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- Squarefree Number
- yes
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Appears in sequences
- a(0) = 1, a(n) = 19*n^2 + 2 for n>0.at n=18A010009
- Exactly half of first a(n) terms of A022300 are 1's (not known to be infinite).at n=33A025513
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 78.at n=5A031576
- Numbers n such that digits of n and the prime factorization of n are distinct and nonrepeating.at n=29A057885
- a(n) = prime(n)^2 - prime(n+1).at n=21A062235
- Expansion of 1/((1-x)*(1+x+2*x^2+x^3)).at n=33A077913
- (p*q - 1)/2 where p and q are consecutive odd primes.at n=27A102770
- Number of partitions of n with no part larger than n/2. Also partitions of n into n/2 or fewer parts.at n=31A110618
- Numbers k such that k and k^2 together contain all ten digits.at n=15A122477
- 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, 0, 1), (0, 1, 0), (1, 1, -1)}.at n=7A150213
- Number of binary strings of length n with equal numbers of 01001 and 10010 substrings.at n=13A164259
- Partial sums of A023201.at n=39A172295
- Total sum of odd parts in the last section of the set of partitions of n.at n=24A206435
- 1/4 the number of (n+1) X 8 0..2 arrays with every 2 X 2 subblock having distinct clockwise edge differences.at n=23A209726
- Number of partitions of n in which all parts are less than n/2.at n=31A210249
- Number of -2..2 arrays x(i) of n+1 elements i=1..n+1 with set{t,u,v in 0,1}((x[i+t]+x[j+u]+x[k+v])*(-1)^(t+u+v)) having two, four or five distinct values for every i,j,k<=n.at n=9A211569
- Number of partitions p of n such that max(p)-min(p) = 6.at n=38A218569
- Duplicate of A210249.at n=30A233771
- Numbers k such that 1 + k + k^3 + k^5 + k^7 + k^9 + ... + k^45 is prime.at n=23A244387
- Number of (n+2) X (3+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000001 00000101 or 00000111.at n=7A261706