1220120656 has 20 divisors (see below), whose sum is σ = 2365395604. Its totient is φ = 609696000.

The previous prime is 1220120653. The next prime is 1220120659. The reversal of 1220120656 is 6560210221.

It is an interprime number because it is at equal distance from previous prime (1220120653) and next prime (1220120659).

It can be written as a sum of positive squares in 2 ways, for example, as 212693056 + 1007427600 = 14584^2 + 31740^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1220120656.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220120653) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5956 + ... + 49756.

Almost surely, 2^1220120656 is an apocalyptic number.

1220120656 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1220120656 is a deficient number, since it is larger than the sum of its proper divisors (1145274948).

1220120656 is a wasteful number, since it uses less digits than its factorization.

1220120656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45550 (or 45544 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 1220120656 is about 34930.2255360597. The cubic root of 1220120656 is about 1068.5649542672.

Adding to 1220120656 its reverse (6560210221), we get a palindrome (7780330877).

The spelling of 1220120656 in words is "one billion, two hundred twenty million, one hundred twenty thousand, six hundred fifty-six".