1221120120220 has 1152 divisors, whose sum is σ = 3843745726464. Its totient is φ = 321995520000.

The previous prime is 1221120120217. The next prime is 1221120120293. The reversal of 1221120120220 is 220210211221.

It is a happy number.

It is a super-2 number, since 2×1221120120220² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1221120120194 and 1221120120203.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 12090298170 + ... + 12090298270.

It is an arithmetic number, because the mean of its divisors is an integer number (3336584832).

Almost surely, 2^{1221120120220} is an apocalyptic number.

1221120120220 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 1221120120220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1921872863232).

1221120120220 is an abundant number, since it is smaller than the sum of its proper divisors (2622625606244).

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

1221120120220 is a wasteful number, since it uses less digits than its factorization.

1221120120220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 224 (or 193 counting only the distinct ones).

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

Adding to 1221120120220 its reverse (220210211221), we get a palindrome (1441330331441).

The spelling of 1221120120220 in words is "one trillion, two hundred twenty-one billion, one hundred twenty million, one hundred twenty thousand, two hundred twenty".