exponential factorial of 4; a superperfect number 262,468 = Leyland number 268,705 = Leyland number 274,177 = prime factor of the Fermat number F6 275,807/195,025 ≈ √2 277,200 = highly composite number 279,841 = 234 279,936 = 67 280,859 = a prime number whose square 78881777881 is tridigital 293,547 = Wedderburn–Etherington number 294,001 = smallest weakly prime number in base 10 294,685 = Markov number 298,320 = Keith number 300,000 to 399,999 310,572 = Motzkin number 317,811 = Fibonacci number 318,682 = Kaprekar number 325,878 = Fine number 326,981 = alternating factorial 329,967 = Kaprekar number 331,776 = 244 332,640 = highly composite number; harmonic divisor number 333,333 = repdigit 333,667 = sexy prime and unique prime 333,673 = sexy prime with 333,679 333,679 = sexy prime with 333,673 337,500 = 22 × 33 × 55 351,351 = only known odd abundant number that is not the sum of some of its proper, nontrivial (i.e. >1) divisors . 351,352 = Kaprekar number 355,419 = Keith number 356,643 = Kaprekar number 360,360 = harmonic divisor number; the smallest number divisible by all of the numbers 1 through 15 362,880 = 9!, highly totient number 370,261 = first prime followed by a prime gap of over 100 371,293 = 135, palindromic in base 12 (15AA5112) 389,305 = self-descriptive number in base 7 390,313 = Kaprekar number 390,625 = 58 397,585 = Leyland number 400,000 to 499,999 409,113 = sum of the first nine factorials 422,481 = smallest number whose fourth power is the sum of three smaller fourth powers 423,393 = Leyland number 426,389 = Markov number 426,569 = cyclic number in base 12 437,760 to 440,319 = any of these numbers will cause the Apple II+ and Apple IIe computers to crash to a monitor prompt when entered at the BASIC prompt, due to a short-cut in the Applesoft code programming of the overflow test when evaluating 16-bit numbers. Entering 440000 at the prompt has been used to hack games that are protected against entering commands at the prompt after the game is loaded. 444,444 = repdigit 456,976 = 264 461,539 = Kaprekar number 466,830 = Kaprekar number 470,832 = Pell number 483,840 = highly totient number 498,960 = highly composite number 499,393 = Markov number 499,500 = Kaprekar number 500,000 to 599,999 500,500 = Kaprekar number, sum of first 1,000 integers 509,203 = Riesel number 510,510 = the product of