1221000331200 has 168 divisors, whose sum is σ = 4314044852208. Its totient is φ = 300553912320.

The previous prime is 1221000331189. The next prime is 1221000331207. The reversal of 1221000331200 is 21330001221.

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 1221000331200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221000331207) by changing a digit.

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, 9721257 + ... + 9846056.

It is an arithmetic number, because the mean of its divisors is an integer number (25678838406).

Almost surely, 2^{1221000331200} is an apocalyptic number.

1221000331200 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221000331200 is an abundant number, since it is smaller than the sum of its proper divisors (3093044521008).

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

1221000331200 is a wasteful number, since it uses less digits than its factorization.

1221000331200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19567351 (or 19567336 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 1221000331200 its reverse (21330001221), we get a palindrome (1242330332421).

The spelling of 1221000331200 in words is "one trillion, two hundred twenty-one billion, three hundred thirty-one thousand, two hundred".