21100002120120 has 256 divisors, whose sum is σ = 78960808903680. Its totient is φ = 4382120448000.

The previous prime is 21100002120107. The next prime is 21100002120157. The reversal of 21100002120120 is 2102120000112.

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

It is a junction number, because it is equal to n+sod(n) for n = 21100002120096 and 21100002120105.

It is a congruent number.

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 63 ways as a sum of consecutive naturals, for example, 17079270 + ... + 18272970.

It is an arithmetic number, because the mean of its divisors is an integer number (308440659780).

Almost surely, 2^{21100002120120} is an apocalyptic number.

21100002120120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21100002120120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39480404451840).

21100002120120 is an abundant number, since it is smaller than the sum of its proper divisors (57860806783560).

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

21100002120120 is a wasteful number, since it uses less digits than its factorization.

21100002120120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1195646 (or 1195642 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21100002120120 its reverse (2102120000112), we get a palindrome (23202122120232).

The spelling of 21100002120120 in words is "twenty-one trillion, one hundred billion, two million, one hundred twenty thousand, one hundred twenty".