12685352021221 has 16 divisors (see below), whose sum is σ = 13902000353280. Its totient is φ = 11479294180080.

The previous prime is 12685352021191. The next prime is 12685352021311. The reversal of 12685352021221 is 12212025358621.

It is a cyclic number.

It is not a de Polignac number, because 12685352021221 - 2⁷ = 12685352021093 is a prime.

It is a super-4 number, since 4×12685352021221⁴ (a number of 54 digits) contains 4444 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12685352021921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13681660 + ... + 14579386.

It is an arithmetic number, because the mean of its divisors is an integer number (868875022080).

Almost surely, 2^{12685352021221} is an apocalyptic number.

12685352021221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12685352021221 is a deficient number, since it is larger than the sum of its proper divisors (1216648332059).

12685352021221 is a wasteful number, since it uses less digits than its factorization.

12685352021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 903624.

The product of its (nonzero) digits is 115200, while the sum is 40.

Adding to 12685352021221 its reverse (12212025358621), we get a palindrome (24897377379842).

The spelling of 12685352021221 in words is "twelve trillion, six hundred eighty-five billion, three hundred fifty-two million, twenty-one thousand, two hundred twenty-one".