1220533556 has 48 divisors (see below), whose sum is σ = 2420288640. Its totient is φ = 533473920.

The previous prime is 1220533549. The next prime is 1220533579. The reversal of 1220533556 is 6553350221.

It is a super-2 number, since 2×1220533556² = 2979404322644010272, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 333770 + ... + 337406.

It is an arithmetic number, because the mean of its divisors is an integer number (50422680).

Almost surely, 2^1220533556 is an apocalyptic number.

It is an amenable number.

1220533556 is a deficient number, since it is larger than the sum of its proper divisors (1199755084).

1220533556 is a wasteful number, since it uses less digits than its factorization.

1220533556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3944 (or 3942 counting only the distinct ones).

The product of its (nonzero) digits is 27000, while the sum is 32.

The square root of 1220533556 is about 34936.1353901659. The cubic root of 1220533556 is about 1068.6854780605.

Adding to 1220533556 its reverse (6553350221), we get a palindrome (7773883777).

The spelling of 1220533556 in words is "one billion, two hundred twenty million, five hundred thirty-three thousand, five hundred fifty-six".