1220001220 has 48 divisors (see below), whose sum is σ = 2630050416. Its totient is φ = 475200000.

The previous prime is 1220001199. The next prime is 1220001221. The reversal of 1220001220 is 221000221.

It can be written as a sum of positive squares in 8 ways, for example, as 54051904 + 1165949316 = 7352^2 + 34146^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 1220001197 and 1220001206.

It is not an unprimeable number, because it can be changed into a prime (1220001221) 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 15 ways as a sum of consecutive naturals, for example, 118270 + ... + 128170.

It is an arithmetic number, because the mean of its divisors is an integer number (54792717).

Almost surely, 2^1220001220 is an apocalyptic number.

1220001220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1220001220 is an abundant number, since it is smaller than the sum of its proper divisors (1410049196).

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

1220001220 is a wasteful number, since it uses less digits than its factorization.

1220001220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10072 (or 10070 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 1220001220 is about 34928.5158573908. The cubic root of 1220001220 is about 1068.5300863253.

Adding to 1220001220 its reverse (221000221), we get a palindrome (1441001441).

Subtracting from 1220001220 its reverse (221000221), we obtain a palindrome (999000999).

It can be divided in two parts, 1220001 and 220, that added together give a palindrome (1220221).

The spelling of 1220001220 in words is "one billion, two hundred twenty million, one thousand, two hundred twenty".