21203320122209 has 4 divisors (see below), whose sum is σ = 21285823313604. Its totient is φ = 21120816930816.

The previous prime is 21203320122191. The next prime is 21203320122241. The reversal of 21203320122209 is 90222102330212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 18266734081600 + 2936586040609 = 4273960^2 + 1713647^2 .

It is a cyclic number.

It is not a de Polignac number, because 21203320122209 - 2¹⁶ = 21203320056673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21203320122269) 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, 41251595312 + ... + 41251595825.

It is an arithmetic number, because the mean of its divisors is an integer number (5321455828401).

Almost surely, 2^{21203320122209} is an apocalyptic number.

It is an amenable number.

21203320122209 is a deficient number, since it is larger than the sum of its proper divisors (82503191395).

21203320122209 is an equidigital number, since it uses as much as digits as its factorization.

21203320122209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82503191394.

The product of its (nonzero) digits is 5184, while the sum is 29.

The spelling of 21203320122209 in words is "twenty-one trillion, two hundred three billion, three hundred twenty million, one hundred twenty-two thousand, two hundred nine".