11581261 has 2 divisors, whose sum is σ = 11581262. Its totient is φ = 11581260.

The previous prime is 11581253. The next prime is 11581331. The reversal of 11581261 is 16218511.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8584900 + 2996361 = 2930^2 + 1731^2 .

It is a cyclic number.

It is not a de Polignac number, because 11581261 - 2³ = 11581253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11588261) 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, 5790630 + 5790631.

It is an arithmetic number, because the mean of its divisors is an integer number (5790631).

Almost surely, 2^11581261 is an apocalyptic number.

It is an amenable number.

11581261 is a deficient number, since it is larger than the sum of its proper divisors (1).

11581261 is an equidigital number, since it uses as much as digits as its factorization.

11581261 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 11581261 is about 3403.1251813590. The cubic root of 11581261 is about 226.2482783260.

Adding to 11581261 its reverse (16218511), we get a palindrome (27799772).

The spelling of 11581261 in words is "eleven million, five hundred eighty-one thousand, two hundred sixty-one".