21000120211 has 16 divisors (see below), whose sum is σ = 24391687680. Its totient is φ = 17707556160.

The previous prime is 21000120187. The next prime is 21000120217. The reversal of 21000120211 is 11202100012.

It is not a de Polignac number, because 21000120211 - 2¹⁵ = 21000087443 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21000120217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 180900 + ... + 273358.

It is an arithmetic number, because the mean of its divisors is an integer number (1524480480).

Almost surely, 2^21000120211 is an apocalyptic number.

21000120211 is a deficient number, since it is larger than the sum of its proper divisors (3391567469).

21000120211 is an equidigital number, since it uses as much as digits as its factorization.

21000120211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92994.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21000120211 its reverse (11202100012), we get a palindrome (32202220223).

The spelling of 21000120211 in words is "twenty-one billion, one hundred twenty thousand, two hundred eleven".