21211001122111 has 4 divisors (see below), whose sum is σ = 21501562781392. Its totient is φ = 20920439462832.

The previous prime is 21211001122061. The next prime is 21211001122183. The reversal of 21211001122111 is 11122110011212.

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 21211001122111 - 2⁹ = 21211001121599 is a prime.

It is a super-2 number, since 2×21211001122111² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211001152111) 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, 145280829531 + ... + 145280829676.

It is an arithmetic number, because the mean of its divisors is an integer number (5375390695348).

Almost surely, 2^{21211001122111} is an apocalyptic number.

21211001122111 is a deficient number, since it is larger than the sum of its proper divisors (290561659281).

21211001122111 is an equidigital number, since it uses as much as digits as its factorization.

21211001122111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 290561659280.

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

Adding to 21211001122111 its reverse (11122110011212), we get a palindrome (32333111133323).

The spelling of 21211001122111 in words is "twenty-one trillion, two hundred eleven billion, one million, one hundred twenty-two thousand, one hundred eleven".