26563236561 has 24 divisors (see below), whose sum is σ = 38749568000. Its totient is φ = 17533799136.

The previous prime is 26563236527. The next prime is 26563236607. The reversal of 26563236561 is 16563236562.

26563236561 is a `hidden beast` number, since 2 + 6 + 5 + 63 + 23 + 6 + 561 = 666.

It is not a de Polignac number, because 26563236561 - 2¹¹ = 26563234513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (26563236361) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 547071 + ... + 593643.

Almost surely, 2^26563236561 is an apocalyptic number.

It is an amenable number.

26563236561 is a deficient number, since it is larger than the sum of its proper divisors (12186331439).

26563236561 is a wasteful number, since it uses less digits than its factorization.

26563236561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47205 (or 47202 counting only the distinct ones).

The product of its digits is 1166400, while the sum is 45.

Subtracting from 26563236561 its reverse (16563236562), we obtain a palindrome (9999999999).

The spelling of 26563236561 in words is "twenty-six billion, five hundred sixty-three million, two hundred thirty-six thousand, five hundred sixty-one".