26091781 has 2 divisors, whose sum is σ = 26091782. Its totient is φ = 26091780.

The previous prime is 26091773. The next prime is 26091799. The reversal of 26091781 is 18719062.

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., 25553025 + 538756 = 5055^2 + 734^2 .

It is a cyclic number.

It is not a de Polignac number, because 26091781 - 2³ = 26091773 is a prime.

It is a super-2 number, since 2×26091781² = 1361562071503922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (26091581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13045890 + 13045891.

It is an arithmetic number, because the mean of its divisors is an integer number (13045891).

Almost surely, 2^26091781 is an apocalyptic number.

It is an amenable number.

26091781 is a deficient number, since it is larger than the sum of its proper divisors (1).

26091781 is an equidigital number, since it uses as much as digits as its factorization.

26091781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6048, while the sum is 34.

The square root of 26091781 is about 5108.0114526105. The cubic root of 26091781 is about 296.5977882990.

The spelling of 26091781 in words is "twenty-six million, ninety-one thousand, seven hundred eighty-one".