21535325305 has 8 divisors (see below), whose sum is σ = 27830266632. Its totient is φ = 15903009408.

The previous prime is 21535325281. The next prime is 21535325321. The reversal of 21535325305 is 50352353512.

It can be written as a sum of positive squares in 4 ways, for example, as 515834944 + 21019490361 = 22712^2 + 144981^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21535325305 - 2³³ = 12945390713 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 165656284 + ... + 165656413.

It is an arithmetic number, because the mean of its divisors is an integer number (3478783329).

Almost surely, 2^21535325305 is an apocalyptic number.

It is an amenable number.

21535325305 is a deficient number, since it is larger than the sum of its proper divisors (6294941327).

21535325305 is a wasteful number, since it uses less digits than its factorization.

21535325305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 331312715.

The product of its (nonzero) digits is 67500, while the sum is 34.

Adding to 21535325305 its reverse (50352353512), we get a palindrome (71887678817).

The spelling of 21535325305 in words is "twenty-one billion, five hundred thirty-five million, three hundred twenty-five thousand, three hundred five".