60,000

Selected numbers in the range 60,000–69,999

60,001 to 60,999

• 60,049 = Leyland number using 3 & 10
• 60,101 = smallest prime with period of reciprocal 100

  61,000 to 61,999

• 61,776 = 2⁴ x 3³ x 11 x 13 = 1⁵ + 2⁵ + 3⁵ + 4⁵ + 5⁵ + 6⁵ + 7⁵ + 8⁵. It is an untouchable number, a triangular number, hexagonal number, 100-gonal number, and is polygonal in 6 other ways.

  62,000 to 62,999

• 62,208 = 3-smooth number
• 62,210 = Markov number
• 62,745 = Carmichael number

  63,000 to 63,999

• 63,020 = amicable number with 76084
• 63,261 = number of partitions of 43
• 63,360 = inches in a mile
• 63,600 = number of free 12-ominoes
• 63,750 = pentagonal pyramidal number
• 63,973 = Carmichael number

  64,000 to 64,999

• 64,000 = 40³
• 64,009 = sum of the cubes of the first 22 positive integers
• 64,079 = Lucas number
• 64,442 = Number of integer degree intersections on Earth: 360 longitudes * 179 latitudes + 2 poles = 64442.
• 64,620 : It is an untouchable number, a triangular number, hexagonal number, and a number such that pi = 64620/10.

  65,000 to 65,999

• 65,025 = 255², palindromic in base 11
• 65,535 = largest value for an unsigned 16-bit integer on a computer.
• 65,536 = 2¹⁶ = 4⁸ = 16⁴ = 256² also 2↑↑4=2↑↑↑3 using Knuth's up-arrow notation, smallest integer with exactly 17 divisors, palindromic in base 15, number of directed graphs on 4 labeled nodes
• 65,537 = largest known Fermat prime
• 65,539 = the 6544th prime number, and both 6544 and 65539 have digital root of 1; a regular prime; a larger member of a twin prime pair; a smaller member of a cousin prime pair; a happy prime; a weak prime; a middle member of a prime triplet, ; a middle member of a three-term primes in arithmetic progression,.
• 65,792 = Leyland number using 2 & 16

  66,000 to 66,999

• 66,012 = tribonacci number
• 66,049 = 257², palindromic in hexadecimal
• 66,198 = Giuga number
• 66,666 = repdigit

  67,000 to 67,999

• 67,081 = 259², palindromic in base 6
• 67,171 = 1⁶ + 2⁶ + 3⁶ + 4⁶ + 5⁶ + 6⁶
• 67,607 = largest of five remaining Seventeen or Bust numbers in the Sierpiński problem
• 67,626 = pentagonal pyramidal number

  68,000 to 68,999

• 68,906 = number of prime numbers having six digits.
• 68,921 = 41³

  69,000 to 69,999

• 69,632 = Leyland number using 4 & 8
• 69,696 = square of 264; only known palindromic square that can be expressed as the sum of a pair of twin primes: 69,696 = 34847 + 34849.
• 69,984 = 3-smooth number

  Primes