21002221102109 has 32 divisors (see below), whose sum is σ = 23249985141600. Its totient is φ = 18854114660352.

The previous prime is 21002221102001. The next prime is 21002221102117. The reversal of 21002221102109 is 90120112220012.

It can be written as a sum of positive squares in 16 ways, for example, as 5597553787225 + 15404667314884 = 2365915^2 + 3924878^2 .

It is a cyclic number.

It is not a de Polignac number, because 21002221102109 - 2²⁰ = 21002220053533 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002221102129) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18829859 + ... + 19914015.

It is an arithmetic number, because the mean of its divisors is an integer number (726562035675).

Almost surely, 2^{21002221102109} is an apocalyptic number.

It is an amenable number.

21002221102109 is a deficient number, since it is larger than the sum of its proper divisors (2247764039491).

21002221102109 is a wasteful number, since it uses less digits than its factorization.

21002221102109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1084529.

The product of its (nonzero) digits is 288, while the sum is 23.

The spelling of 21002221102109 in words is "twenty-one trillion, two billion, two hundred twenty-one million, one hundred two thousand, one hundred nine".