21106126800 has 720 divisors, whose sum is σ = 85399534080. Its totient is φ = 4942080000.

The previous prime is 21106126777. The next prime is 21106126829. The reversal of 21106126800 is 862160112.

It is a tau number, because it is divible by the number of its divisors (720).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 40510540 + ... + 40511060.

It is an arithmetic number, because the mean of its divisors is an integer number (118610464).

Almost surely, 2^21106126800 is an apocalyptic number.

21106126800 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 21106126800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42699767040).

21106126800 is an abundant number, since it is smaller than the sum of its proper divisors (64293407280).

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

21106126800 is a wasteful number, since it uses less digits than its factorization.

21106126800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 601 (or 573 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

Adding to 21106126800 its reverse (862160112), we get a palindrome (21968286912).

The spelling of 21106126800 in words is "twenty-one billion, one hundred six million, one hundred twenty-six thousand, eight hundred".