15031
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 10
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 15032
- 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
- 15030
- Möbius Function
- -1
- Radical
- 15031
- 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
- 208
- 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
- 1757
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Primes p such that q-p = 22, where q is the next prime after p.at n=28A061779
- a(1) = 2; a(n) = largest prime not exceeding the sum of all previous terms.at n=14A070805
- Sums of groups in A075635.at n=28A075636
- a(n) = 1 + Sum(prime(i)*(2*i-1): 1<=i<=n).at n=18A083215
- Indices of prime numbers in A014259.at n=10A101761
- Numbers n such that concatenating n and the sum of factorials of the digits of n produces a square.at n=5A108220
- a(n) = a(n-1) + a(n-3) + a(n-5), with a(1..5) = 1.at n=24A109543
- Primes congruent to 24 mod 43.at n=39A142273
- Primes congruent to 32 mod 53.at n=30A142562
- Primes congruent to 45 mod 59.at n=30A142772
- Primes congruent to 25 mod 61.at n=33A142823
- 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, 0), (0, -1, 1), (0, 1, 0), (1, 1, -1), (1, 1, 1)}.at n=7A150878
- Numbers k such that (sum of base-2 digits of k) = (sum of base-10 digits of k) = 10.at n=25A152207
- Primes p such that p*floor(p/2) - 4 and p*floor(p/2) + 4 are prime numbers.at n=24A164622
- Hypercomma numbers: n occurs in the sequence S[k+1]=S[k]+10*last_digit(S[k-1])+first_digit(S[k]) for each "legal" splitting n=concat(S[0],S[1]).at n=36A166508
- 3-comma numbers: n occurs in the sequence S[k+1]=S[k]+10*last_digit(S[k-1])+first_digit(S[k]) for three different splittings n=concat(S[0],S[1]).at n=13A166513
- Primes p such that p plus or minus the sum of the fourth powers of its digits is a prime in both cases.at n=18A179595
- Number of strings of numbers x(i=1..4) in 0..n with sum i*x(i) equal to n*4.at n=40A184704
- Number of nondecreasing arrangements of 10 numbers in 0..n with the last equal to n and each after the second equal to the sum of one or two of the preceding four.at n=37A189333
- Numbers k such that the periodic part of the continued fraction of sqrt(k) has more ones than any smaller k.at n=29A206579