21100120020100 has 36 divisors (see below), whose sum is σ = 49949738668368. Its totient is φ = 7672770916000.

The previous prime is 21100120020061. The next prime is 21100120020127. The reversal of 21100120020100 is 102002100112.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9590962546 + ... + 9590964745.

It is an arithmetic number, because the mean of its divisors is an integer number (1387492740788).

Almost surely, 2^{21100120020100} is an apocalyptic number.

21100120020100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21100120020100 is an abundant number, since it is smaller than the sum of its proper divisors (28849618648268).

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

21100120020100 is a wasteful number, since it uses less digits than its factorization.

21100120020100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19181927316 (or 19181927309 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21100120020100 its reverse (102002100112), we get a palindrome (21202122120212).

The spelling of 21100120020100 in words is "twenty-one trillion, one hundred billion, one hundred twenty million, twenty thousand, one hundred".