21010122112 has 128 divisors (see below), whose sum is σ = 50812107840. Its totient is φ = 8447459328.

The previous prime is 21010122079. The next prime is 21010122121. The reversal of 21010122112 is 21122101012.

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-2 number, since 2×21010122112² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21010122092 and 21010122101.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5131138 + ... + 5135230.

Almost surely, 2^21010122112 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21010122112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25406053920).

21010122112 is an abundant number, since it is smaller than the sum of its proper divisors (29801985728).

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

21010122112 is a wasteful number, since it uses less digits than its factorization.

21010122112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4468 (or 4456 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21010122112 its reverse (21122101012), we get a palindrome (42132223124).

It can be divided in two parts, 2101012 and 2112, that multiplied together give a palindrome (4437337344).

The spelling of 21010122112 in words is "twenty-one billion, ten million, one hundred twenty-two thousand, one hundred twelve".