12121220100 has 288 divisors, whose sum is σ = 40349417472. Its totient is φ = 2782080000.

The previous prime is 12121220093. The next prime is 12121220101. The reversal of 12121220100 is 102212121.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is not an unprimeable number, because it can be changed into a prime (12121220101) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 4806840 + ... + 4809360.

It is an arithmetic number, because the mean of its divisors is an integer number (140102144).

Almost surely, 2^12121220100 is an apocalyptic number.

12121220100 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 12121220100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20174708736).

12121220100 is an abundant number, since it is smaller than the sum of its proper divisors (28228197372).

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

12121220100 is a wasteful number, since it uses less digits than its factorization.

12121220100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2627 (or 2620 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 12121220100 its reverse (102212121), we get a palindrome (12223432221).

It can be divided in two parts, 12121 and 220100, that added together give a triangular number (232221 = T₆₈₁).

The spelling of 12121220100 in words is "twelve billion, one hundred twenty-one million, two hundred twenty thousand, one hundred".