26531264691 has 8 divisors (see below), whose sum is σ = 39305577360. Its totient is φ = 17687509776.

The previous prime is 26531264677. The next prime is 26531264729. The reversal of 26531264691 is 19646213562.

26531264691 is a `hidden beast` number, since 2 + 6 + 531 + 26 + 4 + 6 + 91 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-26531264691 is a prime.

It is a super-2 number, since 2×26531264691² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (26531264611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 491319690 + ... + 491319743.

It is an arithmetic number, because the mean of its divisors is an integer number (4913197170).

Almost surely, 2^26531264691 is an apocalyptic number.

26531264691 is a deficient number, since it is larger than the sum of its proper divisors (12774312669).

26531264691 is an equidigital number, since it uses as much as digits as its factorization.

26531264691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 982639442 (or 982639436 counting only the distinct ones).

The product of its digits is 466560, while the sum is 45.

The spelling of 26531264691 in words is "twenty-six billion, five hundred thirty-one million, two hundred sixty-four thousand, six hundred ninety-one".