21120001211 has 4 divisors (see below), whose sum is σ = 21313762800. Its totient is φ = 20926239624.

The previous prime is 21120001207. The next prime is 21120001219. The reversal of 21120001211 is 11210002112.

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 21120001211 - 2² = 21120001207 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21120001192 and 21120001201.

It is not an unprimeable number, because it can be changed into a prime (21120001219) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 96880631 + ... + 96880848.

It is an arithmetic number, because the mean of its divisors is an integer number (5328440700).

Almost surely, 2^21120001211 is an apocalyptic number.

21120001211 is a deficient number, since it is larger than the sum of its proper divisors (193761589).

21120001211 is a wasteful number, since it uses less digits than its factorization.

21120001211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193761588.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21120001211 its reverse (11210002112), we get a palindrome (32330003323).

Subtracting from 21120001211 its reverse (11210002112), we obtain a palindrome (9909999099).

The spelling of 21120001211 in words is "twenty-one billion, one hundred twenty million, one thousand, two hundred eleven".