26991086189 has 4 divisors (see below), whose sum is σ = 27141874560. Its totient is φ = 26840297820.

The previous prime is 26991086179. The next prime is 26991086249. The reversal of 26991086189 is 98168019962.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 98168019962 = 2 ⋅49084009981.

It is a cyclic number.

It is not a de Polignac number, because 26991086189 - 2⁴ = 26991086173 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26991086149) 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 in 3 ways as a sum of consecutive naturals, for example, 75393917 + ... + 75394274.

It is an arithmetic number, because the mean of its divisors is an integer number (6785468640).

Almost surely, 2^26991086189 is an apocalyptic number.

It is an amenable number.

26991086189 is a deficient number, since it is larger than the sum of its proper divisors (150788371).

26991086189 is a wasteful number, since it uses less digits than its factorization.

26991086189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150788370.

The product of its (nonzero) digits is 3359232, while the sum is 59.

The spelling of 26991086189 in words is "twenty-six billion, nine hundred ninety-one million, eighty-six thousand, one hundred eighty-nine".