12840561 has 24 divisors (see below), whose sum is σ = 19859840. Its totient is φ = 7970400.

The previous prime is 12840551. The next prime is 12840571. The reversal of 12840561 is 16504821.

It is an interprime number because it is at equal distance from previous prime (12840551) and next prime (12840571).

It is not a de Polignac number, because 12840561 - 2¹⁰ = 12839537 is a prime.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a zygodrome in base 3.

It is not an unprimeable number, because it can be changed into a prime (12840551) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9816 + ... + 11046.

Almost surely, 2^12840561 is an apocalyptic number.

It is an amenable number.

12840561 is a deficient number, since it is larger than the sum of its proper divisors (7019279).

12840561 is a wasteful number, since it uses less digits than its factorization.

12840561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1317 (or 1314 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 12840561 is about 3583.3728524953. The cubic root of 12840561 is about 234.1682441155.

The spelling of 12840561 in words is "twelve million, eight hundred forty thousand, five hundred sixty-one".