Those Fascinating Numbers 205

24 251

• the prime number which appears the most often as 18th prime factor of an

integer (see the number 199).

24 335

• the tenth number n such that n2 − 1 is powerful (see the number 485).

24 384

• the fifth solution of

σ(n)

n

=

8

3

(see the number 1 488).

24 576

• the 16th Granville number (see the number 126).

24 692

• the smallest number n which allows the sum

m≤n

ω(m)=2

1

m

to exceed 4 (see the

number 44).

24 846

• the eighth number which is not a palindrome, but whose square is a palindrome

(see the number 26).

24 885

• the second solution of σ(n) = σ(n + 69) (see the number 8 786).

24 961

• the eighth number whose square can be written as the sum of three fourth

powers: 24

9612

=

604

+

654

+

1564

(see the number 481).

25 200

• the smallest product common to four triplets of numbers having same sum

and same product, these triplets being (6,56,75), (7,40,90), (9,28,100) and

(12,20,105) (Problem E2872, Amer. Math. Monthly 89 (1982), p.499);

• the

24th

highly composite number (see the number 180).