21101001000209 has 16 divisors (see below), whose sum is σ = 23920443583680. Its totient is φ = 18452480840640.

The previous prime is 21101001000197. The next prime is 21101001000229. The reversal of 21101001000209 is 90200010010112.

It is a cyclic number.

It is not a de Polignac number, because 21101001000209 - 2⁴ = 21101001000193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21101001000229) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22793054 + ... + 23700744.

It is an arithmetic number, because the mean of its divisors is an integer number (1495027723980).

Almost surely, 2^{21101001000209} is an apocalyptic number.

It is an amenable number.

21101001000209 is a deficient number, since it is larger than the sum of its proper divisors (2819442583471).

21101001000209 is a wasteful number, since it uses less digits than its factorization.

21101001000209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1001840.

The product of its (nonzero) digits is 36, while the sum is 17.

The spelling of 21101001000209 in words is "twenty-one trillion, one hundred one billion, one million, two hundred nine", and thus it is an aban number.