20111121212 has 192 divisors, whose sum is σ = 45508829184. Its totient is φ = 7567257600.

The previous prime is 20111121211. The next prime is 20111121241. The reversal of 20111121212 is 21212111102.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20111121211) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 177974468 + ... + 177974580.

It is an arithmetic number, because the mean of its divisors is an integer number (237025152).

Almost surely, 2^20111121212 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 20111121212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22754414592).

20111121212 is an abundant number, since it is smaller than the sum of its proper divisors (25397707972).

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

20111121212 is a wasteful number, since it uses less digits than its factorization.

20111121212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 388 (or 386 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 20111121212 its reverse (21212111102), we get a palindrome (41323232314).

The spelling of 20111121212 in words is "twenty billion, one hundred eleven million, one hundred twenty-one thousand, two hundred twelve".