1223206556 has 96 divisors (see below), whose sum is σ = 2625509376. Its totient is φ = 491040000.

The previous prime is 1223206553. The next prime is 1223206571. The reversal of 1223206556 is 6556023221.

It is a super-2 number, since 2×1223206556² = 2992468557282762272, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1223206553) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1790591 + ... + 1791273.

It is an arithmetic number, because the mean of its divisors is an integer number (27349056).

Almost surely, 2^1223206556 is an apocalyptic number.

It is an amenable number.

1223206556 is an abundant number, since it is smaller than the sum of its proper divisors (1402302820).

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

1223206556 is a wasteful number, since it uses less digits than its factorization.

1223206556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 843 (or 841 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 32.

The square root of 1223206556 is about 34974.3699871778. The cubic root of 1223206556 is about 1069.4650588328.

Adding to 1223206556 its reverse (6556023221), we get a palindrome (7779229777).

The spelling of 1223206556 in words is "one billion, two hundred twenty-three million, two hundred six thousand, five hundred fifty-six".