1223205555 has 64 divisors (see below), whose sum is σ = 2306465280. Its totient is φ = 545740800.

The previous prime is 1223205553. The next prime is 1223205589. The reversal of 1223205555 is 5555023221.

It is not a de Polignac number, because 1223205555 - 2¹ = 1223205553 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1223205551) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 898075 + ... + 899435.

It is an arithmetic number, because the mean of its divisors is an integer number (36038520).

Almost surely, 2^1223205555 is an apocalyptic number.

1223205555 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1223205555 is a deficient number, since it is larger than the sum of its proper divisors (1083259725).

1223205555 is a wasteful number, since it uses less digits than its factorization.

1223205555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1812.

The product of its (nonzero) digits is 15000, while the sum is 30.

The square root of 1223205555 is about 34974.3556766955. The cubic root of 1223205555 is about 1069.4647671037.

Adding to 1223205555 its reverse (5555023221), we get a palindrome (6778228776).

The spelling of 1223205555 in words is "one billion, two hundred twenty-three million, two hundred five thousand, five hundred fifty-five".