21513060305 has 32 divisors (see below), whose sum is σ = 28314316800. Its totient is φ = 15561789120.

The previous prime is 21513060263. The next prime is 21513060313. The reversal of 21513060305 is 50306031512.

It is not a de Polignac number, because 21513060305 - 2²⁶ = 21445951441 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 31 ways as a sum of consecutive naturals, for example, 10248146 + ... + 10250244.

It is an arithmetic number, because the mean of its divisors is an integer number (884822400).

Almost surely, 2^21513060305 is an apocalyptic number.

It is an amenable number.

21513060305 is a deficient number, since it is larger than the sum of its proper divisors (6801256495).

21513060305 is a wasteful number, since it uses less digits than its factorization.

21513060305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3029.

The product of its (nonzero) digits is 2700, while the sum is 26.

Adding to 21513060305 its reverse (50306031512), we get a palindrome (71819091817).

The spelling of 21513060305 in words is "twenty-one billion, five hundred thirteen million, sixty thousand, three hundred five".