21201010120209 has 4 divisors (see below), whose sum is σ = 28268013493616. Its totient is φ = 14134006746804.

The previous prime is 21201010120201. The next prime is 21201010120313. The reversal of 21201010120209 is 90202101010212.

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 not a de Polignac number, because 21201010120209 - 2³ = 21201010120201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21201010120201) 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, 3533501686699 + ... + 3533501686704.

It is an arithmetic number, because the mean of its divisors is an integer number (7067003373404).

Almost surely, 2^{21201010120209} is an apocalyptic number.

It is an amenable number.

21201010120209 is a deficient number, since it is larger than the sum of its proper divisors (7067003373407).

21201010120209 is an equidigital number, since it uses as much as digits as its factorization.

21201010120209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7067003373406.

The product of its (nonzero) digits is 144, while the sum is 21.

The spelling of 21201010120209 in words is "twenty-one trillion, two hundred one billion, ten million, one hundred twenty thousand, two hundred nine".