21220121200 has 30 divisors (see below), whose sum is σ = 50981342144. Its totient is φ = 8488048320.

The previous prime is 21220121183. The next prime is 21220121203. The reversal of 21220121200 is 212102212.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220121203) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 26524752 + ... + 26525551.

Almost surely, 2^21220121200 is an apocalyptic number.

21220121200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21220121200 is an abundant number, since it is smaller than the sum of its proper divisors (29761220944).

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

21220121200 is a wasteful number, since it uses less digits than its factorization.

21220121200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53050321 (or 53050310 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21220121200 its reverse (212102212), we get a palindrome (21432223412).

It can be divided in two parts, 2122012 and 1200, that added together give a palindrome (2123212).

The spelling of 21220121200 in words is "twenty-one billion, two hundred twenty million, one hundred twenty-one thousand, two hundred".