26036691721 has 2 divisors, whose sum is σ = 26036691722. Its totient is φ = 26036691720.

The previous prime is 26036691691. The next prime is 26036691763. The reversal of 26036691721 is 12719663062.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16832208121 + 9204483600 = 129739^2 + 95940^2 .

It is a cyclic number.

It is not a de Polignac number, because 26036691721 - 2¹³ = 26036683529 is a prime.

It is not a weakly prime, because it can be changed into another prime (26036611721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13018345860 + 13018345861.

It is an arithmetic number, because the mean of its divisors is an integer number (13018345861).

Almost surely, 2^26036691721 is an apocalyptic number.

It is an amenable number.

26036691721 is a deficient number, since it is larger than the sum of its proper divisors (1).

26036691721 is an equidigital number, since it uses as much as digits as its factorization.

26036691721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 163296, while the sum is 43.

The spelling of 26036691721 in words is "twenty-six billion, thirty-six million, six hundred ninety-one thousand, seven hundred twenty-one".