21221201105 has 32 divisors (see below), whose sum is σ = 27954719520. Its totient is φ = 15370352640.

The previous prime is 21221201087. The next prime is 21221201117. The reversal of 21221201105 is 50110212212.

It can be written as a sum of positive squares in 16 ways, for example, as 12524519569 + 8696681536 = 111913^2 + 93256^2 .

It is not a de Polignac number, because 21221201105 - 2⁸ = 21221200849 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, 846491 + ... + 871199.

It is an arithmetic number, because the mean of its divisors is an integer number (873584985).

Almost surely, 2^21221201105 is an apocalyptic number.

It is an amenable number.

21221201105 is a deficient number, since it is larger than the sum of its proper divisors (6733518415).

21221201105 is a wasteful number, since it uses less digits than its factorization.

21221201105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24981.

The product of its (nonzero) digits is 80, while the sum is 17.

Adding to 21221201105 its reverse (50110212212), we get a palindrome (71331413317).

The spelling of 21221201105 in words is "twenty-one billion, two hundred twenty-one million, two hundred one thousand, one hundred five".