12221555 has 16 divisors (see below), whose sum is σ = 15798240. Its totient is φ = 9042432.

The previous prime is 12221543. The next prime is 12221593. The reversal of 12221555 is 55512221.

It is a cyclic number.

It is not a de Polignac number, because 12221555 - 2⁶ = 12221491 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12221555.

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, 3797 + ... + 6233.

It is an arithmetic number, because the mean of its divisors is an integer number (987390).

Almost surely, 2^12221555 is an apocalyptic number.

12221555 is a deficient number, since it is larger than the sum of its proper divisors (3576685).

12221555 is a wasteful number, since it uses less digits than its factorization.

12221555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2518.

The product of its digits is 1000, while the sum is 23.

The square root of 12221555 is about 3495.9340668840. The cubic root of 12221555 is about 230.3432492987.

Adding to 12221555 its reverse (55512221), we get a palindrome (67733776).

The spelling of 12221555 in words is "twelve million, two hundred twenty-one thousand, five hundred fifty-five".