21012100102000 has 320 divisors, whose sum is σ = 58218445209600. Its totient is φ = 7185198182400.

The previous prime is 21012100101977. The next prime is 21012100102003. The reversal of 21012100102000 is 20100121012.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012100102003) 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, 16428537361 + ... + 16428538639.

It is an arithmetic number, because the mean of its divisors is an integer number (181932641280).

Almost surely, 2^{21012100102000} is an apocalyptic number.

21012100102000 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 21012100102000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29109222604800).

21012100102000 is an abundant number, since it is smaller than the sum of its proper divisors (37206345107600).

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

21012100102000 is a wasteful number, since it uses less digits than its factorization.

21012100102000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3481 (or 3465 counting only the distinct ones).

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

Adding to 21012100102000 its reverse (20100121012), we get a palindrome (21032200223012).

The spelling of 21012100102000 in words is "twenty-one trillion, twelve billion, one hundred million, one hundred two thousand".