21211002002120 has 192 divisors, whose sum is σ = 55767692663280. Its totient is φ = 7239512899584.

The previous prime is 21211002002107. The next prime is 21211002002123. The reversal of 21211002002120 is 2120020011212.

It can be written as a sum of positive squares in 8 ways, for example, as 1804492502596 + 19406509499524 = 1343314^2 + 4405282^2 .

It is a Harshad number since it is a multiple of its sum of digits (14).

It is a junction number, because it is equal to n+sod(n) for n = 21211002002095 and 21211002002104.

It is not an unprimeable number, because it can be changed into a prime (21211002002123) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 431294972 + ... + 431344148.

Almost surely, 2^{21211002002120} is an apocalyptic number.

21211002002120 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 21211002002120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27883846331640).

21211002002120 is an abundant number, since it is smaller than the sum of its proper divisors (34556690661160).

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

21211002002120 is a wasteful number, since it uses less digits than its factorization.

21211002002120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50192 (or 50181 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21211002002120 its reverse (2120020011212), we get a palindrome (23331022013332).

The spelling of 21211002002120 in words is "twenty-one trillion, two hundred eleven billion, two million, two thousand, one hundred twenty".