11451581 has 2 divisors, whose sum is σ = 11451582. Its totient is φ = 11451580.

The previous prime is 11451571. The next prime is 11451589. The reversal of 11451581 is 18515411.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10023556 + 1428025 = 3166^2 + 1195^2 .

It is an emirp because it is prime and its reverse (18515411) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11451581 is a prime.

It is a super-2 number, since 2×11451581² = 262277414799122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 11451581.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11451589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5725790 + 5725791.

It is an arithmetic number, because the mean of its divisors is an integer number (5725791).

Almost surely, 2^11451581 is an apocalyptic number.

It is an amenable number.

11451581 is a deficient number, since it is larger than the sum of its proper divisors (1).

11451581 is an equidigital number, since it uses as much as digits as its factorization.

11451581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 800, while the sum is 26.

The square root of 11451581 is about 3384.0184692167. The cubic root of 11451581 is about 225.4006425576.

Adding to 11451581 its reverse (18515411), we get a palindrome (29966992).

The spelling of 11451581 in words is "eleven million, four hundred fifty-one thousand, five hundred eighty-one".