21121111012212 has 432 divisors, whose sum is σ = 60135950714112. Its totient is φ = 6236610969600.

The previous prime is 21121111012201. The next prime is 21121111012237. The reversal of 21121111012212 is 21221011112112.

It is a happy number.

21121111012212 is a `hidden beast` number, since 211 + 211 + 110 + 122 + 12 = 666.

It is a super-2 number, since 2×21121111012212² (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 an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 4036135548 + ... + 4036140780.

It is an arithmetic number, because the mean of its divisors is an integer number (139203589616).

Almost surely, 2^{21121111012212} 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 21121111012212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30067975357056).

21121111012212 is an abundant number, since it is smaller than the sum of its proper divisors (39014839701900).

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

21121111012212 is a wasteful number, since it uses less digits than its factorization.

21121111012212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5568 (or 5546 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 21121111012212 its reverse (21221011112112), we get a palindrome (42342122124324).

The spelling of 21121111012212 in words is "twenty-one trillion, one hundred twenty-one billion, one hundred eleven million, twelve thousand, two hundred twelve".