1221211200000 has 960 divisors, whose sum is σ = 4499633255040. Its totient is φ = 291840000000.

The previous prime is 1221211199983. The next prime is 1221211200043. The reversal of 1221211200000 is 21121221.

It is a tau number, because it is divible by the number of its divisors (960).

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

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 5332799886 + ... + 5332800114.

It is an arithmetic number, because the mean of its divisors is an integer number (4687117974).

Almost surely, 2^{1221211200000} is an apocalyptic number.

1221211200000 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 1221211200000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2249816627520).

1221211200000 is an abundant number, since it is smaller than the sum of its proper divisors (3278422055040).

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

1221211200000 is an equidigital number, since it uses as much as digits as its factorization.

1221211200000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 387 (or 351 counting only the distinct ones).

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

Adding to 1221211200000 its reverse (21121221), we get a palindrome (1221232321221).

The spelling of 1221211200000 in words is "one trillion, two hundred twenty-one billion, two hundred eleven million, two hundred thousand".