26721296717 has 2 divisors, whose sum is σ = 26721296718. Its totient is φ = 26721296716.

The previous prime is 26721296689. The next prime is 26721296743. The reversal of 26721296717 is 71769212762.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25987374436 + 733922281 = 161206^2 + 27091^2 .

It is a cyclic number.

It is not a de Polignac number, because 26721296717 - 2¹⁶ = 26721231181 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (26721296747) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13360648358 + 13360648359.

It is an arithmetic number, because the mean of its divisors is an integer number (13360648359).

Almost surely, 2^26721296717 is an apocalyptic number.

It is an amenable number.

26721296717 is a deficient number, since it is larger than the sum of its proper divisors (1).

26721296717 is an equidigital number, since it uses as much as digits as its factorization.

26721296717 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 889056, while the sum is 50.

The spelling of 26721296717 in words is "twenty-six billion, seven hundred twenty-one million, two hundred ninety-six thousand, seven hundred seventeen".