21203021112 has 256 divisors, whose sum is σ = 70032936960. Its totient is φ = 5190303744.

The previous prime is 21203021107. The next prime is 21203021141. The reversal of 21203021112 is 21112030212.

It is a junction number, because it is equal to n+sod(n) for n = 21203021091 and 21203021100.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2706433 + ... + 2714255.

It is an arithmetic number, because the mean of its divisors is an integer number (273566160).

Almost surely, 2^21203021112 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 21203021112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35016468480).

21203021112 is an abundant number, since it is smaller than the sum of its proper divisors (48829915848).

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

21203021112 is a wasteful number, since it uses less digits than its factorization.

21203021112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7942 (or 7938 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 21203021112 its reverse (21112030212), we get a palindrome (42315051324).

The spelling of 21203021112 in words is "twenty-one billion, two hundred three million, twenty-one thousand, one hundred twelve".