21520414305 has 24 divisors (see below), whose sum is σ = 40171441128. Its totient is φ = 10594665216.

The previous prime is 21520414243. The next prime is 21520414319. The reversal of 21520414305 is 50341402512.

21520414305 is a `hidden beast` number, since 21 + 5 + 204 + 1 + 430 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 404496 + 21520009809 = 636^2 + 146697^2 .

It is not a de Polignac number, because 21520414305 - 2⁷ = 21520414177 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18392932 + ... + 18394101.

It is an arithmetic number, because the mean of its divisors is an integer number (1673810047).

Almost surely, 2^21520414305 is an apocalyptic number.

It is an amenable number.

21520414305 is a deficient number, since it is larger than the sum of its proper divisors (18651026823).

21520414305 is a wasteful number, since it uses less digits than its factorization.

21520414305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36787057 (or 36787054 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

Adding to 21520414305 its reverse (50341402512), we get a palindrome (71861816817).

The spelling of 21520414305 in words is "twenty-one billion, five hundred twenty million, four hundred fourteen thousand, three hundred five".