21123385122 has 192 divisors, whose sum is σ = 53326872576. Its totient is φ = 5459235840.

The previous prime is 21123385121. The next prime is 21123385187. The reversal of 21123385122 is 22158332112.

21123385122 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 21123385122.

It is not an unprimeable number, because it can be changed into a prime (21123385121) 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, 34799343 + ... + 34799949.

It is an arithmetic number, because the mean of its divisors is an integer number (277744128).

Almost surely, 2^21123385122 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21123385122, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26663436288).

21123385122 is an abundant number, since it is smaller than the sum of its proper divisors (32203487454).

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

21123385122 is a wasteful number, since it uses less digits than its factorization.

21123385122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 761 (or 744 counting only the distinct ones).

The product of its digits is 5760, while the sum is 30.

The spelling of 21123385122 in words is "twenty-one billion, one hundred twenty-three million, three hundred eighty-five thousand, one hundred twenty-two".