21012221011100 has 108 divisors (see below), whose sum is σ = 50586888685032. Its totient is φ = 7569397756800.

The previous prime is 21012221011099. The next prime is 21012221011123. The reversal of 21012221011100 is 111012221012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 6820007 + ... + 9409406.

It is an arithmetic number, because the mean of its divisors is an integer number (468397117454).

Almost surely, 2^{21012221011100} is an apocalyptic number.

21012221011100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21012221011100 is an abundant number, since it is smaller than the sum of its proper divisors (29574667673932).

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

21012221011100 is a wasteful number, since it uses less digits than its factorization.

21012221011100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16229556 (or 16229538 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21012221011100 its reverse (111012221012), we get a palindrome (21123233232112).

The spelling of 21012221011100 in words is "twenty-one trillion, twelve billion, two hundred twenty-one million, eleven thousand, one hundred".