21144000000 has 280 divisors, whose sum is σ = 70490191464. Its totient is φ = 5632000000.

The previous prime is 21143999999. The next prime is 21144000029. The reversal of 21144000000 is 44112.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21144000000.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 23999560 + ... + 24000440.

Almost surely, 2^21144000000 is an apocalyptic number.

21144000000 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 21144000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35245095732).

21144000000 is an abundant number, since it is smaller than the sum of its proper divisors (49346191464).

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

21144000000 is an frugal number, since it uses more digits than its factorization.

21144000000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 932 (or 891 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 12.

Adding to 21144000000 its reverse (44112), we get a palindrome (21144044112).

The spelling of 21144000000 in words is "twenty-one billion, one hundred forty-four million", and thus it is an aban number.