21404775240 has 48 divisors (see below), whose sum is σ = 69565520700. Its totient is φ = 5707939968.

The previous prime is 21404775229. The next prime is 21404775241. The reversal of 21404775240 is 4257740412.

21404775240 is a `hidden beast` number, since 2 + 1 + 404 + 7 + 7 + 5 + 240 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 20803446756 + 601328484 = 144234^2 + 24522^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 21404775195 and 21404775204.

It is not an unprimeable number, because it can be changed into a prime (21404775241) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 29728495 + ... + 29729214.

Almost surely, 2^21404775240 is an apocalyptic number.

21404775240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21404775240 is an abundant number, since it is smaller than the sum of its proper divisors (48160745460).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21404775240 is a wasteful number, since it uses less digits than its factorization.

21404775240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59457726 (or 59457719 counting only the distinct ones).

The product of its (nonzero) digits is 62720, while the sum is 36.

The spelling of 21404775240 in words is "twenty-one billion, four hundred four million, seven hundred seventy-five thousand, two hundred forty".