12120421100 has 72 divisors (see below), whose sum is σ = 28274856960. Its totient is φ = 4495245120.

The previous prime is 12120421097. The next prime is 12120421109. The reversal of 12120421100 is 112402121.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (12120421109) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21437 + ... + 157163.

Almost surely, 2^12120421100 is an apocalyptic number.

12120421100 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 12120421100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14137428480).

12120421100 is an abundant number, since it is smaller than the sum of its proper divisors (16154435860).

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

12120421100 is a wasteful number, since it uses less digits than its factorization.

12120421100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135807 (or 135800 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 12120421100 its reverse (112402121), we get a palindrome (12232823221).

The spelling of 12120421100 in words is "twelve billion, one hundred twenty million, four hundred twenty-one thousand, one hundred".