21011002122 has 64 divisors (see below), whose sum is σ = 47394385920. Its totient is φ = 6152025600.

The previous prime is 21011002087. The next prime is 21011002141. The reversal of 21011002122 is 22120011012.

21011002122 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 21011002098 and 21011002107.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1369329 + ... + 1384587.

It is an arithmetic number, because the mean of its divisors is an integer number (740537280).

Almost surely, 2^21011002122 is an apocalyptic number.

21011002122 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21011002122, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23697192960).

21011002122 is an abundant number, since it is smaller than the sum of its proper divisors (26383383798).

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

21011002122 is a wasteful number, since it uses less digits than its factorization.

21011002122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15979.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21011002122 its reverse (22120011012), we get a palindrome (43131013134).

The spelling of 21011002122 in words is "twenty-one billion, eleven million, two thousand, one hundred twenty-two".