21203121300 has 144 divisors (see below), whose sum is σ = 63085795584. Its totient is φ = 5495040000.

The previous prime is 21203121271. The next prime is 21203121311. The reversal of 21203121300 is 312130212.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21203121300.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3330120 + ... + 3336480.

Almost surely, 2^21203121300 is an apocalyptic number.

21203121300 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 21203121300, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31542897792).

21203121300 is an abundant number, since it is smaller than the sum of its proper divisors (41882674284).

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

21203121300 is a wasteful number, since it uses less digits than its factorization.

21203121300 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6690 (or 6683 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 21203121300 its reverse (312130212), we get a palindrome (21515251512).

The spelling of 21203121300 in words is "twenty-one billion, two hundred three million, one hundred twenty-one thousand, three hundred".