1220320656 has 60 divisors (see below), whose sum is σ = 3616104492. Its totient is φ = 382844928.

The previous prime is 1220320649. The next prime is 1220320669. The reversal of 1220320656 is 6560230221.

1220320656 is a `hidden beast` number, since 1 + 2 + 2 + 0 + 3 + 2 + 0 + 656 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 740710656 + 479610000 = 27216^2 + 21900^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 246801 + ... + 251696.

Almost surely, 2^1220320656 is an apocalyptic number.

1220320656 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1220320656 is an abundant number, since it is smaller than the sum of its proper divisors (2395783836).

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

1220320656 is a wasteful number, since it uses less digits than its factorization.

1220320656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 498528 (or 498519 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 1220320656 is about 34933.0882688605. The cubic root of 1220320656 is about 1068.6233368307.

Adding to 1220320656 its reverse (6560230221), we get a palindrome (7780550877).

The spelling of 1220320656 in words is "one billion, two hundred twenty million, three hundred twenty thousand, six hundred fifty-six".