60,001 to 60,999

• 60,049 = Leyland number^[2]
• 60,101 = smallest prime with period of reciprocal 100^[3]

61,000 to 61,999

• 61,776 = 2⁴ x 3³ x 11 x 13 = 1⁵ + 2⁵ + 3⁵ + 4⁵ + 5⁵ + 6⁵ + 7⁵ + 8⁵.^[4] It is an untouchable number,^[5] a triangular number,^[6] hexagonal number,^[7] 100-gonal number,^[8] and is polygonal in 6 other ways.

62,000 to 62,999

• 62,208 = 3-smooth number
• 62,210 = Markov number^[9]
• 62,745 = Carmichael number^[10]

63,000 to 63,999

• 63,020 = amicable number with 76084
• 63,261 = number of partitions of 43^[11]
• 63,360 = inches in a mile
• 63,600 = number of free 12-ominoes
• 63,750 = pentagonal pyramidal number
• 63,973 = Carmichael number^[10]

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,^[5] a triangular number,^[6] hexagonal number,^[7] and a number such that pi(64620) = 64620/10.^[12]

65,000 to 65,999

• 65,025 = 255², palindromic in base 11 (44944₁₁)
• 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 (14641₁₅), number of directed graphs on 4 labeled nodes^[13]
• 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, (65537, 65539, 65543); a middle member of a three-term primes in arithmetic progression, (65521, 65539, 65557).
• 65,792 = Leyland number^[2]

66,000 to 66,999

• 66,012 = tribonacci number^[14]
• 66,049 = 257², palindromic in hexadecimal (10201₁₆)
• 66,198 = Giuga number^[15]
• 66,666 = repdigit

67,000 to 67,999

• 67,081 = 259², palindromic in base 6 (1234321₆)
• 67,171 = 1⁶ + 2⁶ + 3⁶ + 4⁶ + 5⁶ + 6^6[16]
• 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.^[17]
• 68,921 = 41³

69,000 to 69,999

• 69,632 = Leyland number^[2]
• 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

There are 878 prime numbers between 60000 and 70000.