21120202010209 has 4 divisors (see below), whose sum is σ = 21801498849280. Its totient is φ = 20438905171140.

The previous prime is 21120202010123. The next prime is 21120202010213. The reversal of 21120202010209 is 90201020202112.

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 a de Polignac number, because none of the positive numbers 2^k-21120202010209 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 21120202010209.

It is not an unprimeable number, because it can be changed into a prime (21120202019209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 340648419489 + ... + 340648419550.

It is an arithmetic number, because the mean of its divisors is an integer number (5450374712320).

Almost surely, 2^{21120202010209} is an apocalyptic number.

It is an amenable number.

21120202010209 is a deficient number, since it is larger than the sum of its proper divisors (681296839071).

21120202010209 is an equidigital number, since it uses as much as digits as its factorization.

21120202010209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 681296839070.

The product of its (nonzero) digits is 288, while the sum is 22.

The spelling of 21120202010209 in words is "twenty-one trillion, one hundred twenty billion, two hundred two million, ten thousand, two hundred nine".