12121000000 has 392 divisors, whose sum is σ = 34289561088. Its totient is φ = 4224000000.

The previous prime is 12120999997. The next prime is 12121000007. The reversal of 12121000000 is 12121.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12121000007) by changing a digit.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 390999985 + ... + 391000015.

Almost surely, 2^12121000000 is an apocalyptic number.

12121000000 is a gapful number since it is divisible by the number (10) 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 12121000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17144780544).

12121000000 is an abundant number, since it is smaller than the sum of its proper divisors (22168561088).

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

12121000000 is an frugal number, since it uses more digits than its factorization.

12121000000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113 (or 78 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 7.

Adding to 12121000000 its reverse (12121), we get a palindrome (12121012121).

Multiplying 12121000000 by its reverse (12121), we get a square (146918641000000 = 12121000²).

12121000000 divided by its reverse (12121) gives a 6-th power (1000000 = 10⁶).

The spelling of 12121000000 in words is "twelve billion, one hundred twenty-one million", and thus it is an aban number.