21002121100212 has 384 divisors, whose sum is σ = 60116791848960. Its totient is φ = 5573637734400.

The previous prime is 21002121100187. The next prime is 21002121100229. The reversal of 21002121100212 is 21200112120012.

It is a junction number, because it is equal to n+sod(n) for n = 21002121100191 and 21002121100200.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 21496541068 + ... + 21496542044.

It is an arithmetic number, because the mean of its divisors is an integer number (156554145440).

Almost surely, 2^{21002121100212} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21002121100212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30058395924480).

21002121100212 is an abundant number, since it is smaller than the sum of its proper divisors (39114670748748).

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

21002121100212 is a wasteful number, since it uses less digits than its factorization.

21002121100212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1991 (or 1989 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21002121100212 its reverse (21200112120012), we get a palindrome (42202233220224).

The spelling of 21002121100212 in words is "twenty-one trillion, two billion, one hundred twenty-one million, one hundred thousand, two hundred twelve".