21021102200 has 144 divisors (see below), whose sum is σ = 58952008080. Its totient is φ = 6827742720.

The previous prime is 21021102107. The next prime is 21021102209. The reversal of 21021102200 is 220112012.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021102209) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 484604 + ... + 526196.

It is an arithmetic number, because the mean of its divisors is an integer number (409388945).

Almost surely, 2^21021102200 is an apocalyptic number.

21021102200 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 21021102200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29476004040).

21021102200 is an abundant number, since it is smaller than the sum of its proper divisors (37930905880).

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

21021102200 is a wasteful number, since it uses less digits than its factorization.

21021102200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41654 (or 41626 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21021102200 its reverse (220112012), we get a palindrome (21241214212).

The spelling of 21021102200 in words is "twenty-one billion, twenty-one million, one hundred two thousand, two hundred".