21211212112120 has 16 divisors (see below), whose sum is σ = 47725227252360. Its totient is φ = 8484484844832.

The previous prime is 21211212112099. The next prime is 21211212112157. The reversal of 21211212112120 is 2121121211212.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 265140151362 + ... + 265140151441.

Almost surely, 2^{21211212112120} is an apocalyptic number.

21211212112120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21211212112120 is an abundant number, since it is smaller than the sum of its proper divisors (26514015140240).

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

21211212112120 is a wasteful number, since it uses less digits than its factorization.

21211212112120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 530280302814 (or 530280302810 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 21211212112120 its reverse (2121121211212), we get a palindrome (23332333323332).

The spelling of 21211212112120 in words is "twenty-one trillion, two hundred eleven billion, two hundred twelve million, one hundred twelve thousand, one hundred twenty".