1001221001220 has 384 divisors, whose sum is σ = 3249724230144. Its totient is φ = 228096000000.

The previous prime is 1001221001203. The next prime is 1001221001227. The reversal of 1001221001220 is 221001221001.

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

It is a junction number, because it is equal to n+sod(n) for n = 1001221001196 and 1001221001205.

It is not an unprimeable number, because it can be changed into a prime (1001221001227) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 101118270 + ... + 101128170.

It is an arithmetic number, because the mean of its divisors is an integer number (8462823516).

Almost surely, 2^{1001221001220} is an apocalyptic number.

1001221001220 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 1001221001220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1624862115072).

1001221001220 is an abundant number, since it is smaller than the sum of its proper divisors (2248503228924).

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

1001221001220 is a wasteful number, since it uses less digits than its factorization.

1001221001220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10103 (or 10101 counting only the distinct ones).

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

Adding to 1001221001220 its reverse (221001221001), we get a palindrome (1222222222221).

The spelling of 1001221001220 in words is "one trillion, one billion, two hundred twenty-one million, one thousand, two hundred twenty".