1221220013120 has 224 divisors, whose sum is σ = 3140394621408. Its totient is φ = 450617802752.

The previous prime is 1221220013099. The next prime is 1221220013147. The reversal of 1221220013120 is 213100221221.

It can be written as a sum of positive squares in 16 ways, for example, as 100281155584 + 1120938857536 = 316672^2 + 1058744^2 .

It is a Harshad number since it is a multiple of its sum of digits (17).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 430460342 + ... + 430463178.

Almost surely, 2^{1221220013120} is an apocalyptic number.

1221220013120 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 1221220013120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1570197310704).

1221220013120 is an abundant number, since it is smaller than the sum of its proper divisors (1919174608288).

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

1221220013120 is a wasteful number, since it uses less digits than its factorization.

1221220013120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4417 (or 4407 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 1221220013120 its reverse (213100221221), we get a palindrome (1434320234341).

The spelling of 1221220013120 in words is "one trillion, two hundred twenty-one billion, two hundred twenty million, thirteen thousand, one hundred twenty".