21011003200 has 168 divisors, whose sum is σ = 56522721600. Its totient is φ = 7623782400.

The previous prime is 21011003197. The next prime is 21011003203. The reversal of 21011003200 is 230011012.

It is an interprime number because it is at equal distance from previous prime (21011003197) and next prime (21011003203).

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011003203) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10541404 + ... + 10543396.

Almost surely, 2^21011003200 is an apocalyptic number.

21011003200 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 21011003200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28261360800).

21011003200 is an abundant number, since it is smaller than the sum of its proper divisors (35511718400).

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

21011003200 is a wasteful number, since it uses less digits than its factorization.

21011003200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2625 (or 2610 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 10.

Adding to 21011003200 its reverse (230011012), we get a palindrome (21241014212).

The spelling of 21011003200 in words is "twenty-one billion, eleven million, three thousand, two hundred".