21100202121200 has 120 divisors (see below), whose sum is σ = 51532258550256. Its totient is φ = 8301529600000.

The previous prime is 21100202121191. The next prime is 21100202121209. The reversal of 21100202121200 is 212120200112.

It is an interprime number because it is at equal distance from previous prime (21100202121191) and next prime (21100202121209).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21100202121209) 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, 4139450 + ... + 7702950.

Almost surely, 2^{21100202121200} is an apocalyptic number.

21100202121200 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 21100202121200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25766129275128).

21100202121200 is an abundant number, since it is smaller than the sum of its proper divisors (30432056429056).

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

21100202121200 is a wasteful number, since it uses less digits than its factorization.

21100202121200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3563763 (or 3563752 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21100202121200 its reverse (212120200112), we get a palindrome (21312322321312).

The spelling of 21100202121200 in words is "twenty-one trillion, one hundred billion, two hundred two million, one hundred twenty-one thousand, two hundred".