1221241021000 has 768 divisors, whose sum is σ = 3892510702080. Its totient is φ = 348961536000.

The previous prime is 1221241020943. The next prime is 1221241021001. The reversal of 1221241021000 is 1201421221.

It is not an unprimeable number, because it can be changed into a prime (1221241021001) 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 191 ways as a sum of consecutive naturals, for example, 2169166719 + ... + 2169167281.

It is an arithmetic number, because the mean of its divisors is an integer number (5068373310).

Almost surely, 2^{1221241021000} is an apocalyptic number.

1221241021000 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 1221241021000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1946255351040).

1221241021000 is an abundant number, since it is smaller than the sum of its proper divisors (2671269681080).

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

1221241021000 is a wasteful number, since it uses less digits than its factorization.

1221241021000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 823 (or 798 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 1221241021000 its reverse (1201421221), we get a palindrome (1222442442221).

The spelling of 1221241021000 in words is "one trillion, two hundred twenty-one billion, two hundred forty-one million, twenty-one thousand".