21520413235 has 16 divisors (see below), whose sum is σ = 26720992800. Its totient is φ = 16618932736.

The previous prime is 21520413227. The next prime is 21520413281. The reversal of 21520413235 is 53231402512.

It is a cyclic number.

It is not a de Polignac number, because 21520413235 - 2³ = 21520413227 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 15 ways as a sum of consecutive naturals, for example, 754056 + ... + 782074.

It is an arithmetic number, because the mean of its divisors is an integer number (1670062050).

Almost surely, 2^21520413235 is an apocalyptic number.

21520413235 is a deficient number, since it is larger than the sum of its proper divisors (5200579565).

21520413235 is a wasteful number, since it uses less digits than its factorization.

21520413235 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33350.

The product of its (nonzero) digits is 7200, while the sum is 28.

Adding to 21520413235 its reverse (53231402512), we get a palindrome (74751815747).

The spelling of 21520413235 in words is "twenty-one billion, five hundred twenty million, four hundred thirteen thousand, two hundred thirty-five".