Those Fascinating Numbers 353

16 720 797 973 (= 115 · 473)

• the 10

000th

3-powerful number (see the number 216).

19 391 512 145

• the

16th

Euler number (see the number 272).

21 111 311 232

• the

19th

insolite number (see the number 111).

22 801 415 981

• the 1 000 000

000th

prime power, in fact here a prime number (see the number

419).

22 801 763 489

• the 1 000 000 000th prime number (see the number 541).

23 040 925 705

• the fifth number which can be written as the sum of the cubes of its prime

factors:

23 040 925 705 = 5 · 7 · 167 · 1453 · 2713 =

53

+

73

+

1673

+

14533

+

27133

(see the number 378).

24 423 128 562 (= 2 · 3 · 7 · 43 · 3041 · 4 447)

• the sixth Giuga number (see the number 30).

24 749 911 296

• the third number n 1 whose sum of digits is equal to

6

√

n (see the number

34 012 224).

25 056 082 087

• the smallest prime number which is followed by at least 400 consecutive compos-

ite numbers (in fact here by exactly 455 composite numbers); see the number

370 261.