21102111010100 has 72 divisors (see below), whose sum is σ = 46339650869400. Its totient is φ = 8339955148800.

The previous prime is 21102111010061. The next prime is 21102111010151. The reversal of 21102111010100 is 101011120112.

It can be written as a sum of positive squares in 12 ways, for example, as 16912442400676 + 4189668609424 = 4112474^2 + 2046868^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11432456 + ... + 13149344.

It is an arithmetic number, because the mean of its divisors is an integer number (643606262075).

Almost surely, 2^{21102111010100} is an apocalyptic number.

21102111010100 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 21102111010100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23169825434700).

21102111010100 is an abundant number, since it is smaller than the sum of its proper divisors (25237539859300).

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

21102111010100 is a wasteful number, since it uses less digits than its factorization.

21102111010100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1718373 (or 1718366 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 11.

Adding to 21102111010100 its reverse (101011120112), we get a palindrome (21203122130212).

The spelling of 21102111010100 in words is "twenty-one trillion, one hundred two billion, one hundred eleven million, ten thousand, one hundred".