2121001002100 has 72 divisors (see below), whose sum is σ = 4716740032928. Its totient is φ = 827415388800.

The previous prime is 2121001002097. The next prime is 2121001002251. The reversal of 2121001002100 is 12001001212.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2469187 + ... + 3215413.

Almost surely, 2^{2121001002100} is an apocalyptic number.

2121001002100 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 2121001002100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2358370016464).

2121001002100 is an abundant number, since it is smaller than the sum of its proper divisors (2595739030828).

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

2121001002100 is a wasteful number, since it uses less digits than its factorization.

2121001002100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 746945 (or 746938 counting only the distinct ones).

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

Adding to 2121001002100 its reverse (12001001212), we get a palindrome (2133002003312).

The spelling of 2121001002100 in words is "two trillion, one hundred twenty-one billion, one million, two thousand, one hundred".