1221101112000 has 448 divisors, whose sum is σ = 5027011292160. Its totient is φ = 253734912000.

The previous prime is 1221101111987. The next prime is 1221101112097. The reversal of 1221101112000 is 2111011221.

It is a tau number, because it is divible by the number of its divisors (448).

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

It is an unprimeable number.

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 63 ways as a sum of consecutive naturals, for example, 1517616 + ... + 2178384.

Almost surely, 2^{1221101112000} is an apocalyptic number.

1221101112000 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 1221101112000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2513505646080).

1221101112000 is an abundant number, since it is smaller than the sum of its proper divisors (3805910180160).

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

1221101112000 is a wasteful number, since it uses less digits than its factorization.

1221101112000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 660817 (or 660797 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 1221101112000 its reverse (2111011221), we get a palindrome (1223212123221).

The spelling of 1221101112000 in words is "one trillion, two hundred twenty-one billion, one hundred one million, one hundred twelve thousand".