12611581 has 2 divisors, whose sum is σ = 12611582. Its totient is φ = 12611580.

The previous prime is 12611519. The next prime is 12611597. The reversal of 12611581 is 18511621.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12538681 + 72900 = 3541^2 + 270^2 .

It is a cyclic number.

It is not a de Polignac number, because 12611581 - 2⁷ = 12611453 is a prime.

It is a super-3 number, since 3×12611581³ (a number of 22 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12611281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6305790 + 6305791.

It is an arithmetic number, because the mean of its divisors is an integer number (6305791).

Almost surely, 2^12611581 is an apocalyptic number.

It is an amenable number.

12611581 is a deficient number, since it is larger than the sum of its proper divisors (1).

12611581 is an equidigital number, since it uses as much as digits as its factorization.

12611581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 480, while the sum is 25.

The square root of 12611581 is about 3551.2787837623. The cubic root of 12611581 is about 232.7679479122.

The spelling of 12611581 in words is "twelve million, six hundred eleven thousand, five hundred eighty-one".