12261581 has 2 divisors, whose sum is σ = 12261582. Its totient is φ = 12261580.

The previous prime is 12261569. The next prime is 12261611. The reversal of 12261581 is 18516221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11792356 + 469225 = 3434^2 + 685^2 .

It is a cyclic number.

It is not a de Polignac number, because 12261581 - 2²² = 8067277 is a prime.

It is a super-2 number, since 2×12261581² = 300692737239122, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12261581.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12261521) 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 as a sum of consecutive naturals, namely, 6130790 + 6130791.

It is an arithmetic number, because the mean of its divisors is an integer number (6130791).

Almost surely, 2^12261581 is an apocalyptic number.

It is an amenable number.

12261581 is a deficient number, since it is larger than the sum of its proper divisors (1).

12261581 is an equidigital number, since it uses as much as digits as its factorization.

12261581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 960, while the sum is 26.

The square root of 12261581 is about 3501.6540377370. The cubic root of 12261581 is about 230.5944358896.

The spelling of 12261581 in words is "twelve million, two hundred sixty-one thousand, five hundred eighty-one".