1221244000000 has 252 divisors, whose sum is σ = 3207681597400. Its totient is φ = 462758400000.

The previous prime is 1221243999977. The next prime is 1221244000007. The reversal of 1221244000000 is 4421221.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221244000007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 75991966 + ... + 76008034.

Almost surely, 2^{1221244000000} is an apocalyptic number.

1221244000000 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 1221244000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1603840798700).

1221244000000 is an abundant number, since it is smaller than the sum of its proper divisors (1986437597400).

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

1221244000000 is an frugal number, since it uses more digits than its factorization.

1221244000000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16134 (or 16095 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 1221244000000 its reverse (4421221), we get a palindrome (1221248421221).

The spelling of 1221244000000 in words is "one trillion, two hundred twenty-one billion, two hundred forty-four million", and thus it is an aban number.