21235403105 has 32 divisors (see below), whose sum is σ = 31113231360. Its totient is φ = 13589104320.

The previous prime is 21235403083. The next prime is 21235403221. The reversal of 21235403105 is 50130453212.

It is a happy number.

It is not a de Polignac number, because 21235403105 - 2¹⁰ = 21235402081 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, 193751 + ... + 282860.

It is an arithmetic number, because the mean of its divisors is an integer number (972288480).

Almost surely, 2^21235403105 is an apocalyptic number.

It is an amenable number.

21235403105 is a deficient number, since it is larger than the sum of its proper divisors (9877828255).

21235403105 is a wasteful number, since it uses less digits than its factorization.

21235403105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 476709.

The product of its (nonzero) digits is 3600, while the sum is 26.

Adding to 21235403105 its reverse (50130453212), we get a palindrome (71365856317).

The spelling of 21235403105 in words is "twenty-one billion, two hundred thirty-five million, four hundred three thousand, one hundred five".