26091581 has 2 divisors, whose sum is σ = 26091582. Its totient is φ = 26091580.

The previous prime is 26091557. The next prime is 26091601. The reversal of 26091581 is 18519062.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 23716900 + 2374681 = 4870^2 + 1541^2 .

It is a cyclic number.

It is not a de Polignac number, because 26091581 - 2¹⁰ = 26090557 is a prime.

It is a super-2 number, since 2×26091581² = 1361541198159122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (26091781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13045790 + 13045791.

It is an arithmetic number, because the mean of its divisors is an integer number (13045791).

Almost surely, 2^26091581 is an apocalyptic number.

It is an amenable number.

26091581 is a deficient number, since it is larger than the sum of its proper divisors (1).

26091581 is an equidigital number, since it uses as much as digits as its factorization.

26091581 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4320, while the sum is 32.

The square root of 26091581 is about 5107.9918754830. The cubic root of 26091581 is about 296.5970304651.

The spelling of 26091581 in words is "twenty-six million, ninety-one thousand, five hundred eighty-one".