21100221200 has 30 divisors (see below), whose sum is σ = 50693282394. Its totient is φ = 8440088320.

The previous prime is 21100221119. The next prime is 21100221209. The reversal of 21100221200 is 212200112.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 4046995456 + 17053225744 = 63616^2 + 130588^2 .

It is a super-3 number, since 3×21100221200³ (a number of 32 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (21100221209) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 26374877 + ... + 26375676.

Almost surely, 2^21100221200 is an apocalyptic number.

21100221200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21100221200 is an abundant number, since it is smaller than the sum of its proper divisors (29593061194).

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

21100221200 is a wasteful number, since it uses less digits than its factorization.

21100221200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52750571 (or 52750560 counting only the distinct ones).

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

Adding to 21100221200 its reverse (212200112), we get a palindrome (21312421312).

The spelling of 21100221200 in words is "twenty-one billion, one hundred million, two hundred twenty-one thousand, two hundred".