11129581 has 2 divisors, whose sum is σ = 11129582. Its totient is φ = 11129580.

The previous prime is 11129579. The next prime is 11129593. The reversal of 11129581 is 18592111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9400356 + 1729225 = 3066^2 + 1315^2 .

It is an emirp because it is prime and its reverse (18592111) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11129581 - 2¹ = 11129579 is a prime.

It is a super-2 number, since 2×11129581² = 247735146471122, which contains 22 as substring.

Together with 11129579, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11129501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5564790 + 5564791.

It is an arithmetic number, because the mean of its divisors is an integer number (5564791).

Almost surely, 2^11129581 is an apocalyptic number.

It is an amenable number.

11129581 is a deficient number, since it is larger than the sum of its proper divisors (1).

11129581 is an equidigital number, since it uses as much as digits as its factorization.

11129581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 720, while the sum is 28.

The square root of 11129581 is about 3336.1026662859. The cubic root of 11129581 is about 223.2678917689.

It can be divided in two parts, 111 and 29581, that added together give a palindrome (29692).

The spelling of 11129581 in words is "eleven million, one hundred twenty-nine thousand, five hundred eighty-one".