21121211020212 has 144 divisors (see below), whose sum is σ = 53983651018752. Its totient is φ = 6962330007360.

The previous prime is 21121211020211. The next prime is 21121211020267. The reversal of 21121211020212 is 21202011212112.

21121211020212 is a `hidden beast` number, since 211 + 212 + 1 + 10 + 20 + 212 = 666.

It is a super-2 number, since 2×21121211020212² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121211020211) 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, 8151759037 + ... + 8151761627.

It is an arithmetic number, because the mean of its divisors is an integer number (374886465408).

Almost surely, 2^{21121211020212} is an apocalyptic number.

It is an amenable number.

21121211020212 is an abundant number, since it is smaller than the sum of its proper divisors (32862439998540).

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

21121211020212 is a wasteful number, since it uses less digits than its factorization.

21121211020212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5618 (or 5613 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21121211020212 its reverse (21202011212112), we get a palindrome (42323222232324).

The spelling of 21121211020212 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred eleven million, twenty thousand, two hundred twelve".