1220661128 has 16 divisors (see below), whose sum is σ = 2290246080. Its totient is φ = 609928848.

The previous prime is 1220661121. The next prime is 1220661133. The reversal of 1220661128 is 8211660221.

It is a self number, because there is not a number n which added to its sum of digits gives 1220661128.

It is not an unprimeable number, because it can be changed into a prime (1220661121) by changing a digit.

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, 37100 + ... + 61787.

It is an arithmetic number, because the mean of its divisors is an integer number (143140380).

Almost surely, 2^1220661128 is an apocalyptic number.

It is an amenable number.

1220661128 is a deficient number, since it is larger than the sum of its proper divisors (1069584952).

1220661128 is a wasteful number, since it uses less digits than its factorization.

1220661128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100436 (or 100432 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 1220661128 is about 34937.9611311250. The cubic root of 1220661128 is about 1068.7227103003.

The spelling of 1220661128 in words is "one billion, two hundred twenty million, six hundred sixty-one thousand, one hundred twenty-eight".