12840161 has 4 divisors (see below), whose sum is σ = 12850452. Its totient is φ = 12829872.

The previous prime is 12840133. The next prime is 12840193. The reversal of 12840161 is 16104821.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 16104821 = 1699 ⋅9479.

It can be written as a sum of positive squares in 2 ways, for example, as 12737761 + 102400 = 3569^2 + 320^2 .

It is a cyclic number.

It is not a de Polignac number, because 12840161 - 2¹⁰ = 12839137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12840131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2966 + ... + 5871.

It is an arithmetic number, because the mean of its divisors is an integer number (3212613).

Almost surely, 2^12840161 is an apocalyptic number.

It is an amenable number.

12840161 is a deficient number, since it is larger than the sum of its proper divisors (10291).

12840161 is an equidigital number, since it uses as much as digits as its factorization.

12840161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10290.

The product of its (nonzero) digits is 384, while the sum is 23.

The square root of 12840161 is about 3583.3170387226. The cubic root of 12840161 is about 234.1658125429.

Adding to 12840161 its reverse (16104821), we get a palindrome (28944982).

The spelling of 12840161 in words is "twelve million, eight hundred forty thousand, one hundred sixty-one".