12121004400 has 120 divisors (see below), whose sum is σ = 40871253120. Its totient is φ = 3062142720.

The previous prime is 12121004383. The next prime is 12121004443. The reversal of 12121004400 is 440012121.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 12121004400.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 243012 + ... + 288611.

It is an arithmetic number, because the mean of its divisors is an integer number (340593776).

Almost surely, 2^12121004400 is an apocalyptic number.

12121004400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12121004400 is an abundant number, since it is smaller than the sum of its proper divisors (28750248720).

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

12121004400 is a wasteful number, since it uses less digits than its factorization.

12121004400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 531663 (or 531652 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 12121004400 its reverse (440012121), we get a palindrome (12561016521).

The spelling of 12121004400 in words is "twelve billion, one hundred twenty-one million, four thousand, four hundred".