21220121212100 has 36 divisors (see below), whose sum is σ = 47533071522048. Its totient is φ = 8214240468000.

The previous prime is 21220121212091. The next prime is 21220121212117. The reversal of 21220121212100 is 121212102212.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3422597096 + ... + 3422603295.

Almost surely, 2^{21220121212100} is an apocalyptic number.

21220121212100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21220121212100 is an abundant number, since it is smaller than the sum of its proper divisors (26312950309948).

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

21220121212100 is a wasteful number, since it uses less digits than its factorization.

21220121212100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6845200436 (or 6845200429 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21220121212100 its reverse (121212102212), we get a palindrome (21341333314312).

The spelling of 21220121212100 in words is "twenty-one trillion, two hundred twenty billion, one hundred twenty-one million, two hundred twelve thousand, one hundred".