21111122122110 has 192 divisors, whose sum is σ = 57541762998720. Its totient is φ = 5568430924800.

The previous prime is 21111122122067. The next prime is 21111122122117. The reversal of 21111122122110 is 1122122111112.

It is a happy number.

21111122122110 is a `hidden beast` number, since 211 + 1 + 1 + 1 + 221 + 221 + 10 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111122122117) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 253487556 + ... + 253570824.

It is an arithmetic number, because the mean of its divisors is an integer number (299696682285).

Almost surely, 2^{21111122122110} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21111122122110, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28770881499360).

21111122122110 is an abundant number, since it is smaller than the sum of its proper divisors (36430640876610).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21111122122110 is a wasteful number, since it uses less digits than its factorization.

21111122122110 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84425 (or 84413 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 21111122122110 its reverse (1122122111112), we get a palindrome (22233244233222).

The spelling of 21111122122110 in words is "twenty-one trillion, one hundred eleven billion, one hundred twenty-two million, one hundred twenty-two thousand, one hundred ten".