26191077581 has 2 divisors, whose sum is σ = 26191077582. Its totient is φ = 26191077580.

The previous prime is 26191077481. The next prime is 26191077587. The reversal of 26191077581 is 18577019162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 26188948900 + 2128681 = 161830^2 + 1459^2 .

It is a cyclic number.

It is not a de Polignac number, because 26191077581 - 2²² = 26186883277 is a prime.

It is a super-2 number, since 2×26191077581² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (26191077587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13095538790 + 13095538791.

It is an arithmetic number, because the mean of its divisors is an integer number (13095538791).

Almost surely, 2^26191077581 is an apocalyptic number.

It is an amenable number.

26191077581 is a deficient number, since it is larger than the sum of its proper divisors (1).

26191077581 is an equidigital number, since it uses as much as digits as its factorization.

26191077581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 211680, while the sum is 47.

The spelling of 26191077581 in words is "twenty-six billion, one hundred ninety-one million, seventy-seven thousand, five hundred eighty-one".