21002100121002 has 128 divisors (see below), whose sum is σ = 56408764704768. Its totient is φ = 5034440275200.

The previous prime is 21002100120997. The next prime is 21002100121003. The reversal of 21002100121002 is 20012100120012.

It is not an unprimeable number, because it can be changed into a prime (21002100121003) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 29261008 + ... + 29970164.

It is an arithmetic number, because the mean of its divisors is an integer number (440693474256).

Almost surely, 2^{21002100121002} is an apocalyptic number.

21002100121002 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21002100121002, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28204382352384).

21002100121002 is an abundant number, since it is smaller than the sum of its proper divisors (35406664583766).

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

21002100121002 is a wasteful number, since it uses less digits than its factorization.

21002100121002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 714124.

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

Adding to 21002100121002 its reverse (20012100120012), we get a palindrome (41014200241014).

The spelling of 21002100121002 in words is "twenty-one trillion, two billion, one hundred million, one hundred twenty-one thousand, two".