21100212211 has 4 divisors (see below), whose sum is σ = 22723305472. Its totient is φ = 19477118952.

The previous prime is 21100212197. The next prime is 21100212223. The reversal of 21100212211 is 11221200112.

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

It is a cyclic number.

It is not a de Polignac number, because 21100212211 - 2⁵ = 21100212179 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13), and also a Moran number because the ratio is a prime number: 1623093247 = 21100212211 / (2 + 1 + 1 + 0 + 0 + 2 + 1 + 2 + 2 + 1 + 1).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21100212191 and 21100212200.

It is not an unprimeable number, because it can be changed into a prime (21100212241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 811546611 + ... + 811546636.

It is an arithmetic number, because the mean of its divisors is an integer number (5680826368).

Almost surely, 2^21100212211 is an apocalyptic number.

21100212211 is a deficient number, since it is larger than the sum of its proper divisors (1623093261).

21100212211 is a wasteful number, since it uses less digits than its factorization.

21100212211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1623093260.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21100212211 its reverse (11221200112), we get a palindrome (32321412323).

The spelling of 21100212211 in words is "twenty-one billion, one hundred million, two hundred twelve thousand, two hundred eleven".