1220066556 has 72 divisors (see below), whose sum is σ = 3019008384. Its totient is φ = 383386080.

The previous prime is 1220066531. The next prime is 1220066609. The reversal of 1220066556 is 6556600221.

It is a happy number.

It is a super-2 number, since 2×1220066556² = 2977124802139402272, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 449355 + ... + 452061.

It is an arithmetic number, because the mean of its divisors is an integer number (41930672).

Almost surely, 2^1220066556 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1220066556, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1509504192).

1220066556 is an abundant number, since it is smaller than the sum of its proper divisors (1798941828).

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

1220066556 is a wasteful number, since it uses less digits than its factorization.

1220066556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2831 (or 2806 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 33.

The square root of 1220066556 is about 34929.4511265207. The cubic root of 1220066556 is about 1068.5491606875.

Adding to 1220066556 its reverse (6556600221), we get a palindrome (7776666777).

The spelling of 1220066556 in words is "one billion, two hundred twenty million, sixty-six thousand, five hundred fifty-six".