21011121020100 has 144 divisors (see below), whose sum is σ = 64590919041600. Its totient is φ = 5273379023360.

The previous prime is 21011121020081. The next prime is 21011121020111. The reversal of 21011121020100 is 102012111012.

It is a Harshad number since it is a multiple of its sum of digits (12).

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 47 ways as a sum of consecutive naturals, for example, 5653830 + ... + 8601629.

It is an arithmetic number, because the mean of its divisors is an integer number (448548048900).

Almost surely, 2^{21011121020100} is an apocalyptic number.

21011121020100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21011121020100 is an abundant number, since it is smaller than the sum of its proper divisors (43579798021500).

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

21011121020100 is a wasteful number, since it uses less digits than its factorization.

21011121020100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14255527 (or 14255486 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21011121020100 its reverse (102012111012), we get a palindrome (21113133131112).

The spelling of 21011121020100 in words is "twenty-one trillion, eleven billion, one hundred twenty-one million, twenty thousand, one hundred".