12666213257 has 32 divisors (see below), whose sum is σ = 13909969920. Its totient is φ = 11493316800.

The previous prime is 12666213223. The next prime is 12666213319. The reversal of 12666213257 is 75231266621.

It is a cyclic number.

It is not a de Polignac number, because 12666213257 - 2⁶ = 12666213193 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12666213557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10238843 + ... + 10240079.

It is an arithmetic number, because the mean of its divisors is an integer number (434686560).

Almost surely, 2^12666213257 is an apocalyptic number.

It is an amenable number.

12666213257 is a deficient number, since it is larger than the sum of its proper divisors (1243756663).

12666213257 is a wasteful number, since it uses less digits than its factorization.

12666213257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1533.

The product of its digits is 181440, while the sum is 41.

Adding to 12666213257 its reverse (75231266621), we get a palindrome (87897479878).

The spelling of 12666213257 in words is "twelve billion, six hundred sixty-six million, two hundred thirteen thousand, two hundred fifty-seven".