12499
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
- 4
- Divisor Sum
- 12960
- Proper Divisor Sum (Aliquot Sum)
- 461
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12040
- Möbius Function
- 1
- Radical
- 12499
- 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
- 156
- 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
- no
- Odd
- yes
Appears in sequences
- a(n) = floor( n*(n-1)*(n-2)/20 ).at n=64A011902
- a(n) = 1*t(n) + 2*t(n-1) + ... + k*t(n+1-k), where k=floor((n+1)/2) and t = A008578 ({1} U primes).at n=33A023862
- a(n) = 1*prime(n) + 2*prime(n-1) + ... + k*prime(n+1-k), where k=floor((n+1)/2) and prime(n) is the n-th prime.at n=32A023870
- Lucky numbers with size of gaps equal to 20 (lower terms).at n=25A031902
- Numbers k such that k^4 == 1 (mod 5^5).at n=15A056102
- An approximation to sigma_{5/2}(n): floor( sum_{d|n} d^(5/2) ).at n=39A058272
- Number of partitions of n in which the number of parts is relatively prime to n.at n=37A102628
- a(3n) = 3a(3n-1)-3a(3n-2)+2a(3n-3), a(3n+1) = 3a(3n)-3a(3n-1)+2a(3n-2), a(3n+2) = 3a(3n+1)-3a(3n), a(0) = 0, a(1) = 1, a(2) = 2.at n=19A131761
- Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1000-1111-0010 pattern in any orientation.at n=9A146404
- a(n) = 625*n - 1.at n=19A158374
- a(n) = 20*n^2 - 1.at n=24A158491
- Numbers k such that Sum_{i=1..k} i^6 divides Product_{i=1..k} i^6.at n=10A166606
- Numbers of the form i*5^j-1 (i=1..4, j >= 0).at n=23A181287
- Numbers which contain only the digit 4 in their base-5 representation, with at most one exception. If the exception is the most-significant digit, it must be the digit 1, 2, or 3, otherwise the exception must be the digit 3.at n=32A188531
- Union of A071863 and A071861.at n=46A193458
- Numbers n such that sopfr(n-1) | (n+sopfr(n+1)) and sopfr(n+1) | (n+sopfr(n-1)), where sopfr = A001414 (sum of prime factors with repetition).at n=1A196994
- a(n) = 4*5^n-1.at n=5A198763
- Number of 3Xn 0..1 arrays with all rows having a nonnegative second derivative, and all and columns having a positive second derivative in a quadratic least squares fit, with one and two element arrays taken as having a zero second derivative.at n=9A223653
- Values of n such that L(10) and N(10) are both prime, where L(k) = (n^2+n+1)*2^(2*k) + (2*n+1)*2^k + 1, N(k) = (n^2+n+1)*2^k + n.at n=45A227448
- Number of simple connected graphs on n nodes with no cycle of length 5.at n=9A241784