21851112000 has 448 divisors, whose sum is σ = 74495655936. Its totient is φ = 5641574400.

The previous prime is 21851111999. The next prime is 21851112007. The reversal of 21851112000 is 21115812.

It is not an unprimeable number, because it can be changed into a prime (21851112007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 172055937 + ... + 172056063.

Almost surely, 2^21851112000 is an apocalyptic number.

21851112000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21851112000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37247827968).

21851112000 is an abundant number, since it is smaller than the sum of its proper divisors (52644543936).

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

21851112000 is a wasteful number, since it uses less digits than its factorization.

21851112000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 331 (or 311 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 21.

Adding to 21851112000 its reverse (21115812), we get a palindrome (21872227812).

The spelling of 21851112000 in words is "twenty-one billion, eight hundred fifty-one million, one hundred twelve thousand".