12705841821 has 16 divisors (see below), whose sum is σ = 17364106368. Its totient is φ = 8259302400.

The previous prime is 12705841817. The next prime is 12705841843. The reversal of 12705841821 is 12814850721.

It is not a de Polignac number, because 12705841821 - 2² = 12705841817 is a prime.

It is a super-2 number, since 2×12705841821² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 12705841821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12705841121) 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 15 ways as a sum of consecutive naturals, for example, 197005 + ... + 253421.

It is an arithmetic number, because the mean of its divisors is an integer number (1085256648).

Almost surely, 2^12705841821 is an apocalyptic number.

It is an amenable number.

12705841821 is a deficient number, since it is larger than the sum of its proper divisors (4658264547).

12705841821 is a wasteful number, since it uses less digits than its factorization.

12705841821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58292.

The product of its (nonzero) digits is 35840, while the sum is 39.

The spelling of 12705841821 in words is "twelve billion, seven hundred five million, eight hundred forty-one thousand, eight hundred twenty-one".