26809931917 has 2 divisors, whose sum is σ = 26809931918. Its totient is φ = 26809931916.

The previous prime is 26809931891. The next prime is 26809931987. The reversal of 26809931917 is 71913990862.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26211933801 + 597998116 = 161901^2 + 24454^2 .

It is a cyclic number.

It is not a de Polignac number, because 26809931917 - 2⁷ = 26809931789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (26809931987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13404965958 + 13404965959.

It is an arithmetic number, because the mean of its divisors is an integer number (13404965959).

Almost surely, 2^26809931917 is an apocalyptic number.

It is an amenable number.

26809931917 is a deficient number, since it is larger than the sum of its proper divisors (1).

26809931917 is an equidigital number, since it uses as much as digits as its factorization.

26809931917 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1469664, while the sum is 55.

The spelling of 26809931917 in words is "twenty-six billion, eight hundred nine million, nine hundred thirty-one thousand, nine hundred seventeen".