15749
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 26
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 15750
- 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
- 15748
- Möbius Function
- -1
- Radical
- 15749
- 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
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1837
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Number of series-reduced rooted trees with n nodes.at n=19A001679
- Numbers k such that 2*10^k - 1 is prime.at n=23A002957
- Numbers k such that the continued fraction for sqrt(k) has period 67.at n=17A020406
- Erroneous version of A001679.at n=16A037163
- Denominators of continued fraction convergents to sqrt(992).at n=4A042921
- Numbers whose base-5 representation contains exactly three 0's and three 4's.at n=10A045217
- Discriminants of real quadratic fields with class number 1 and related continued fraction period length of 23.at n=24A051964
- Number of homeomorphically irreducible rooted trees (also known as series-reduced rooted trees, or rooted trees without nodes of degree 2) with n >= 1 nodes.at n=19A059123
- Numbers n such that P(13*n) is prime, where P(n) is the unrestricted partition number.at n=15A113518
- Intersection of A061068 and A064270.at n=32A128996
- Primes congruent to 4 mod 47.at n=37A142356
- Primes congruent to 8 mod 53.at n=37A142538
- Primes congruent to 55 mod 59.at n=30A142782
- Primes congruent to 11 mod 61.at n=33A142809
- Triangle T(n, k) = binomial(n, k)^2 - binomial(n, k) - 1, read by rows.at n=49A144403
- Triangle T(n, k) = binomial(n, k)^2 - binomial(n, k) - 1, read by rows.at n=50A144403
- a(n) = 70*n^2 - 1.at n=14A158736
- Primes p such that 2*p^4-+15 are also prime.at n=16A174366
- First of a run of 4 or more consecutive primes which all equal 2 (mod 3).at n=39A185941
- Consider two consecutive primes {p,q} such that {P=2p-q,Q=2q-p} are both prime. Sequence gives lesser primes p.at n=33A186169