21013121112 has 32 divisors (see below), whose sum is σ = 52997701680. Its totient is φ = 6942387200.

The previous prime is 21013121071. The next prime is 21013121113. The reversal of 21013121112 is 21112131012.

It is a junction number, because it is equal to n+sod(n) for n = 21013121091 and 21013121100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21013121113) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3871389 + ... + 3876812.

Almost surely, 2^21013121112 is an apocalyptic number.

It is an amenable number.

21013121112 is an abundant number, since it is smaller than the sum of its proper divisors (31984580568).

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

21013121112 is a wasteful number, since it uses less digits than its factorization.

21013121112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7748323 (or 7748319 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 15.

Adding to 21013121112 its reverse (21112131012), we get a palindrome (42125252124).

It can be divided in two parts, 2101 and 3121112, that added together give a palindrome (3123213).

The spelling of 21013121112 in words is "twenty-one billion, thirteen million, one hundred twenty-one thousand, one hundred twelve".