21000120200109 has 12 divisors (see below), whose sum is σ = 30492321130752. Its totient is φ = 13926781283400.

The previous prime is 21000120200107. The next prime is 21000120200159. The reversal of 21000120200109 is 90100202100012.

It is not a de Polignac number, because 21000120200109 - 2¹ = 21000120200107 is a prime.

It is a super-2 number, since 2×21000120200109² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21000120200091 and 21000120200100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000120200107) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6108235687 + ... + 6108239124.

It is an arithmetic number, because the mean of its divisors is an integer number (2541026760896).

Almost surely, 2^{21000120200109} is an apocalyptic number.

It is an amenable number.

21000120200109 is a deficient number, since it is larger than the sum of its proper divisors (9492200930643).

21000120200109 is a wasteful number, since it uses less digits than its factorization.

21000120200109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12216475008 (or 12216475005 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The spelling of 21000120200109 in words is "twenty-one trillion, one hundred twenty million, two hundred thousand, one hundred nine".