21002111012209 has 4 divisors (see below), whose sum is σ = 21112069708800. Its totient is φ = 20892152315620.

The previous prime is 21002111012171. The next prime is 21002111012221. The reversal of 21002111012209 is 90221011120012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21002111012209 - 2⁷ = 21002111012081 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21002111012209.

It is not an unprimeable number, because it can be changed into a prime (21002111012809) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 54979348009 + ... + 54979348390.

It is an arithmetic number, because the mean of its divisors is an integer number (5278017427200).

Almost surely, 2^{21002111012209} is an apocalyptic number.

It is an amenable number.

21002111012209 is a deficient number, since it is larger than the sum of its proper divisors (109958696591).

21002111012209 is a wasteful number, since it uses less digits than its factorization.

21002111012209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109958696590.

The product of its (nonzero) digits is 144, while the sum is 22.

The spelling of 21002111012209 in words is "twenty-one trillion, two billion, one hundred eleven million, twelve thousand, two hundred nine".