1220221220 has 12 divisors (see below), whose sum is σ = 2562464604. Its totient is φ = 488088480.

The previous prime is 1220221217. The next prime is 1220221241. The reversal of 1220221220 is 221220221.

It can be written as a sum of positive squares in 2 ways, for example, as 422384704 + 797836516 = 20552^2 + 28246^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1220221195 and 1220221204.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30505511 + ... + 30505550.

It is an arithmetic number, because the mean of its divisors is an integer number (213538717).

Almost surely, 2^1220221220 is an apocalyptic number.

1220221220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1220221220 is an abundant number, since it is smaller than the sum of its proper divisors (1342243384).

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

1220221220 is a wasteful number, since it uses less digits than its factorization.

1220221220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61011070 (or 61011068 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

The square root of 1220221220 is about 34931.6650046917. The cubic root of 1220221220 is about 1068.5943109852.

Adding to 1220221220 its reverse (221220221), we get a palindrome (1441441441).

Subtracting from 1220221220 its reverse (221220221), we obtain a palindrome (999000999).

The spelling of 1220221220 in words is "one billion, two hundred twenty million, two hundred twenty-one thousand, two hundred twenty".