21121021222110 has 96 divisors (see below), whose sum is σ = 55145435304960. Its totient is φ = 5608637152704.

The previous prime is 21121021222033. The next prime is 21121021222141. The reversal of 21121021222110 is 1122212012112.

21121021222110 is a `hidden beast` number, since 2 + 11 + 210 + 212 + 221 + 10 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 29011131 + ... + 29730249.

It is an arithmetic number, because the mean of its divisors is an integer number (574431617760).

Almost surely, 2^{21121021222110} is an apocalyptic number.

21121021222110 is an abundant number, since it is smaller than the sum of its proper divisors (34024414082850).

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

21121021222110 is a wasteful number, since it uses less digits than its factorization.

21121021222110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 720502 (or 720499 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21121021222110 its reverse (1122212012112), we get a palindrome (22243233234222).

The spelling of 21121021222110 in words is "twenty-one trillion, one hundred twenty-one billion, twenty-one million, two hundred twenty-two thousand, one hundred ten".