12123355657 has 16 divisors (see below), whose sum is σ = 14237793792. Its totient is φ = 10104868800.

The previous prime is 12123355633. The next prime is 12123355691. The reversal of 12123355657 is 75655332121.

It is a happy number.

12123355657 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 12123355657 - 2¹¹ = 12123353609 is a prime.

It is a super-2 number, since 2×12123355657² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12123355697) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 480048 + ... + 504670.

It is an arithmetic number, because the mean of its divisors is an integer number (889862112).

Almost surely, 2^12123355657 is an apocalyptic number.

It is an amenable number.

12123355657 is a deficient number, since it is larger than the sum of its proper divisors (2114438135).

12123355657 is a wasteful number, since it uses less digits than its factorization.

12123355657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26568.

The product of its digits is 189000, while the sum is 40.

Adding to 12123355657 its reverse (75655332121), we get a palindrome (87778687778).

The spelling of 12123355657 in words is "twelve billion, one hundred twenty-three million, three hundred fifty-five thousand, six hundred fifty-seven".