21100012120100 has 18 divisors (see below), whose sum is σ = 45787026300834. Its totient is φ = 8440004848000.

The previous prime is 21100012120097. The next prime is 21100012120133. The reversal of 21100012120100 is 102121000112.

It can be written as a sum of positive squares in 3 ways, for example, as 342803224036 + 20757208896064 = 585494^2 + 4556008^2 .

It is a super-2 number, since 2×21100012120100² (a number of 27 digits) contains 22 as substring.

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 5 ways as a sum of consecutive naturals, for example, 105500060501 + ... + 105500060700.

Almost surely, 2^{21100012120100} is an apocalyptic number.

21100012120100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21100012120100 is an abundant number, since it is smaller than the sum of its proper divisors (24687014180734).

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

21100012120100 is a wasteful number, since it uses less digits than its factorization.

21100012120100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 211000121215 (or 211000121208 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21100012120100 its reverse (102121000112), we get a palindrome (21202133120212).

The spelling of 21100012120100 in words is "twenty-one trillion, one hundred billion, twelve million, one hundred twenty thousand, one hundred".