1221121200000 has 384 divisors, whose sum is σ = 4366165235040. Its totient is φ = 300579840000.

The previous prime is 1221121199939. The next prime is 1221121200029. The reversal of 1221121200000 is 21211221.

It is a tau number, because it is divible by the number of its divisors (384).

It is a super-2 number, since 2×1221121200000² (a number of 25 digits) contains 22 as substring.

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

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 47 ways as a sum of consecutive naturals, for example, 15560862 + ... + 15639138.

Almost surely, 2^{1221121200000} is an apocalyptic number.

1221121200000 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 1221121200000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2183082617520).

1221121200000 is an abundant number, since it is smaller than the sum of its proper divisors (3145044035040).

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

1221121200000 is an frugal number, since it uses more digits than its factorization.

1221121200000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78332 (or 78300 counting only the distinct ones).

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

Adding to 1221121200000 its reverse (21211221), we get a palindrome (1221142411221).

The spelling of 1221121200000 in words is "one trillion, two hundred twenty-one billion, one hundred twenty-one million, two hundred thousand".