1223221555 has 8 divisors (see below), whose sum is σ = 1477587744. Its totient is φ = 972096000.

The previous prime is 1223221541. The next prime is 1223221561. The reversal of 1223221555 is 5551223221.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1223221555 - 2⁵ = 1223221523 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 809326 + ... + 810835.

It is an arithmetic number, because the mean of its divisors is an integer number (184698468).

Almost surely, 2^1223221555 is an apocalyptic number.

1223221555 is a deficient number, since it is larger than the sum of its proper divisors (254366189).

1223221555 is a wasteful number, since it uses less digits than its factorization.

1223221555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1620317.

The product of its digits is 6000, while the sum is 28.

The square root of 1223221555 is about 34974.5844149720. The cubic root of 1223221555 is about 1069.4694300871.

Adding to 1223221555 its reverse (5551223221), we get a palindrome (6774444776).

It can be divided in two parts, 1223 and 221555, that added together give a triangular number (222778 = T₆₆₇).

The spelling of 1223221555 in words is "one billion, two hundred twenty-three million, two hundred twenty-one thousand, five hundred fifty-five".