21121012221100 has 36 divisors (see below), whose sum is σ = 49999196206008. Its totient is φ = 7680368080000.

The previous prime is 21121012221091. The next prime is 21121012221103. The reversal of 21121012221100 is 112221012112.

It is not an unprimeable number, because it can be changed into a prime (21121012221103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9600459001 + ... + 9600461200.

It is an arithmetic number, because the mean of its divisors is an integer number (1388866561278).

Almost surely, 2^{21121012221100} is an apocalyptic number.

21121012221100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21121012221100 is an abundant number, since it is smaller than the sum of its proper divisors (28878183984908).

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

21121012221100 is a wasteful number, since it uses less digits than its factorization.

21121012221100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19200920226 (or 19200920219 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21121012221100 its reverse (112221012112), we get a palindrome (21233233233212).

The spelling of 21121012221100 in words is "twenty-one trillion, one hundred twenty-one billion, twelve million, two hundred twenty-one thousand, one hundred".