12581681 has 12 divisors (see below), whose sum is σ = 14694372. Its totient is φ = 10741248.

The previous prime is 12581659. The next prime is 12581689. The reversal of 12581681 is 18618521.

It can be written as a sum of positive squares in 2 ways, for example, as 4264225 + 8317456 = 2065^2 + 2884^2 .

It is not a de Polignac number, because 12581681 - 2¹⁴ = 12565297 is a prime.

It is a super-2 number, since 2×12581681² = 316597393571522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (12581689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 20921 + ... + 21513.

It is an arithmetic number, because the mean of its divisors is an integer number (1224531).

Almost surely, 2^12581681 is an apocalyptic number.

It is an amenable number.

12581681 is a deficient number, since it is larger than the sum of its proper divisors (2112691).

12581681 is an equidigital number, since it uses as much as digits as its factorization.

12581681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1040 (or 1033 counting only the distinct ones).

The product of its digits is 3840, while the sum is 32.

The square root of 12581681 is about 3547.0665344761. The cubic root of 12581681 is about 232.5838507439.

The spelling of 12581681 in words is "twelve million, five hundred eighty-one thousand, six hundred eighty-one".