11256416581 has 2 divisors, whose sum is σ = 11256416582. Its totient is φ = 11256416580.

The previous prime is 11256416573. The next prime is 11256416621. The reversal of 11256416581 is 18561465211.

It is an a-pointer prime, because the next prime (11256416621) can be obtained adding 11256416581 to its sum of digits (40).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10597673025 + 658743556 = 102945^2 + 25666^2 .

It is a cyclic number.

It is not a de Polignac number, because 11256416581 - 2³ = 11256416573 is a prime.

It is a super-2 number, since 2×11256416581² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11256426581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5628208290 + 5628208291.

It is an arithmetic number, because the mean of its divisors is an integer number (5628208291).

Almost surely, 2^11256416581 is an apocalyptic number.

It is an amenable number.

11256416581 is a deficient number, since it is larger than the sum of its proper divisors (1).

11256416581 is an equidigital number, since it uses as much as digits as its factorization.

11256416581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 57600, while the sum is 40.

The spelling of 11256416581 in words is "eleven billion, two hundred fifty-six million, four hundred sixteen thousand, five hundred eighty-one".