21201222211100 has 72 divisors (see below), whose sum is σ = 49260262453920. Its totient is φ = 7891955230720.

The previous prime is 21201222211097. The next prime is 21201222211121. The reversal of 21201222211100 is 111222210212.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 69912224 + ... + 70214823.

It is an arithmetic number, because the mean of its divisors is an integer number (684170311860).

Almost surely, 2^{21201222211100} is an apocalyptic number.

21201222211100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21201222211100 is an abundant number, since it is smaller than the sum of its proper divisors (28059040242820).

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

21201222211100 is a wasteful number, since it uses less digits than its factorization.

21201222211100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140127167 (or 140127160 counting only the distinct ones).

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

Adding to 21201222211100 its reverse (111222210212), we get a palindrome (21312444421312).

The spelling of 21201222211100 in words is "twenty-one trillion, two hundred one billion, two hundred twenty-two million, two hundred eleven thousand, one hundred".