21891189112 has 64 divisors (see below), whose sum is σ = 47408004000. Its totient is φ = 9391209984.

The previous prime is 21891189079. The next prime is 21891189127. The reversal of 21891189112 is 21198119812.

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, 214 + ... + 209242.

Almost surely, 2^21891189112 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 21891189112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23704002000).

21891189112 is an abundant number, since it is smaller than the sum of its proper divisors (25516814888).

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

21891189112 is a wasteful number, since it uses less digits than its factorization.

21891189112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209120 (or 209116 counting only the distinct ones).

The product of its digits is 20736, while the sum is 43.

The spelling of 21891189112 in words is "twenty-one billion, eight hundred ninety-one million, one hundred eighty-nine thousand, one hundred twelve".