26561609451 has 16 divisors (see below), whose sum is σ = 42377497120. Its totient is φ = 16345605600.

The previous prime is 26561609429. The next prime is 26561609491. The reversal of 26561609451 is 15490616562.

26561609451 is a `hidden beast` number, since 26 + 5 + 616 + 0 + 9 + 4 + 5 + 1 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-26561609451 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 26561609397 and 26561609406.

It is not an unprimeable number, because it can be changed into a prime (26561609491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37836700 + ... + 37837401.

It is an arithmetic number, because the mean of its divisors is an integer number (2648593570).

Almost surely, 2^26561609451 is an apocalyptic number.

26561609451 is a deficient number, since it is larger than the sum of its proper divisors (15815887669).

26561609451 is a wasteful number, since it uses less digits than its factorization.

26561609451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75674123 (or 75674117 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 45.

The spelling of 26561609451 in words is "twenty-six billion, five hundred sixty-one million, six hundred nine thousand, four hundred fifty-one".