21210112120111 has 4 divisors (see below), whose sum is σ = 21247388240400. Its totient is φ = 21172835999824.

The previous prime is 21210112120069. The next prime is 21210112120117. The reversal of 21210112120111 is 11102121101212.

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 21210112120111 - 2¹⁹ = 21210111595823 is a prime.

It is a super-2 number, since 2×21210112120111² (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 (21210112120117) 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, 18638059291 + ... + 18638060428.

It is an arithmetic number, because the mean of its divisors is an integer number (5311847060100).

Almost surely, 2^{21210112120111} is an apocalyptic number.

21210112120111 is a deficient number, since it is larger than the sum of its proper divisors (37276120289).

21210112120111 is an equidigital number, since it uses as much as digits as its factorization.

21210112120111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37276120288.

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

Adding to 21210112120111 its reverse (11102121101212), we get a palindrome (32312233221323).

The spelling of 21210112120111 in words is "twenty-one trillion, two hundred ten billion, one hundred twelve million, one hundred twenty thousand, one hundred eleven".