21111020112 has 80 divisors (see below), whose sum is σ = 67122231680. Its totient is φ = 5567740416.

The previous prime is 21111020111. The next prime is 21111020123. The reversal of 21111020112 is 21102011112.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111020111) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2412187 + ... + 2420922.

It is an arithmetic number, because the mean of its divisors is an integer number (839027896).

Almost surely, 2^21111020112 is an apocalyptic number.

It is an amenable number.

21111020112 is an abundant number, since it is smaller than the sum of its proper divisors (46011211568).

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

21111020112 is a wasteful number, since it uses less digits than its factorization.

21111020112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4833140 (or 4833134 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21111020112 its reverse (21102011112), we get a palindrome (42213031224).

The spelling of 21111020112 in words is "twenty-one billion, one hundred eleven million, twenty thousand, one hundred twelve".