21124013200 has 60 divisors (see below), whose sum is σ = 50863904100. Its totient is φ = 8430714880.

The previous prime is 21124013161. The next prime is 21124013219. The reversal of 21124013200 is 231042112.

It can be written as a sum of positive squares in 6 ways, for example, as 4373441424 + 16750571776 = 66132^2 + 129424^2 .

It is a Harshad number since it is a multiple of its sum of digits (16).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 120792 + ... + 238408.

It is an arithmetic number, because the mean of its divisors is an integer number (847731735).

Almost surely, 2^21124013200 is an apocalyptic number.

21124013200 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 21124013200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25431952050).

21124013200 is an abundant number, since it is smaller than the sum of its proper divisors (29739890900).

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

21124013200 is a wasteful number, since it uses less digits than its factorization.

21124013200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118084 (or 118073 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 21124013200 its reverse (231042112), we get a palindrome (21355055312).

The spelling of 21124013200 in words is "twenty-one billion, one hundred twenty-four million, thirteen thousand, two hundred".