12121655 has 16 divisors (see below), whose sum is σ = 17903424. Its totient is φ = 7672320.

The previous prime is 12121631. The next prime is 12121661. The reversal of 12121655 is 55612121.

It is a happy number.

It is not a de Polignac number, because 12121655 - 2¹⁰ = 12120631 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12121655.

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, 12866 + ... + 13775.

It is an arithmetic number, because the mean of its divisors is an integer number (1118964).

Almost surely, 2^12121655 is an apocalyptic number.

12121655 is a deficient number, since it is larger than the sum of its proper divisors (5781769).

12121655 is a wasteful number, since it uses less digits than its factorization.

12121655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26666.

The product of its digits is 600, while the sum is 23.

The square root of 12121655 is about 3481.6167221565. The cubic root of 12121655 is about 229.7139165168.

Adding to 12121655 its reverse (55612121), we get a palindrome (67733776).

The spelling of 12121655 in words is "twelve million, one hundred twenty-one thousand, six hundred fifty-five".