21121102211 has 4 divisors (see below), whose sum is σ = 23041202424. Its totient is φ = 19201002000.

The previous prime is 21121102207. The next prime is 21121102267. The reversal of 21121102211 is 11220112112.

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 21121102211 - 2² = 21121102207 is a prime.

It is a super-2 number, since 2×21121102211² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21121102291) 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, 960050090 + ... + 960050111.

It is an arithmetic number, because the mean of its divisors is an integer number (5760300606).

Almost surely, 2^21121102211 is an apocalyptic number.

21121102211 is a deficient number, since it is larger than the sum of its proper divisors (1920100213).

21121102211 is a wasteful number, since it uses less digits than its factorization.

21121102211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1920100212.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21121102211 its reverse (11220112112), we get a palindrome (32341214323).

Subtracting from 21121102211 its reverse (11220112112), we obtain a palindrome (9900990099).

The spelling of 21121102211 in words is "twenty-one billion, one hundred twenty-one million, one hundred two thousand, two hundred eleven".