21100211209 has 8 divisors (see below), whose sum is σ = 26306756928. Its totient is φ = 16441722960.

The previous prime is 21100211191. The next prime is 21100211219. The reversal of 21100211209 is 90211200112.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21100211209 - 2⁹ = 21100210697 is a prime.

It is a super-3 number, since 3×21100211209³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21100211219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 137014282 + ... + 137014435.

It is an arithmetic number, because the mean of its divisors is an integer number (3288344616).

Almost surely, 2^21100211209 is an apocalyptic number.

It is an amenable number.

21100211209 is a deficient number, since it is larger than the sum of its proper divisors (5206545719).

21100211209 is a wasteful number, since it uses less digits than its factorization.

21100211209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 274028735.

The product of its (nonzero) digits is 72, while the sum is 19.

The spelling of 21100211209 in words is "twenty-one billion, one hundred million, two hundred eleven thousand, two hundred nine".