26504047561 has 2 divisors, whose sum is σ = 26504047562. Its totient is φ = 26504047560.

The previous prime is 26504047519. The next prime is 26504047679. The reversal of 26504047561 is 16574040562.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16010093961 + 10493953600 = 126531^2 + 102440^2 .

It is a cyclic number.

It is not a de Polignac number, because 26504047561 - 2⁷ = 26504047433 is a prime.

It is not a weakly prime, because it can be changed into another prime (26504047501) 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 as a sum of consecutive naturals, namely, 13252023780 + 13252023781.

It is an arithmetic number, because the mean of its divisors is an integer number (13252023781).

Almost surely, 2^26504047561 is an apocalyptic number.

It is an amenable number.

26504047561 is a deficient number, since it is larger than the sum of its proper divisors (1).

26504047561 is an equidigital number, since it uses as much as digits as its factorization.

26504047561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 201600, while the sum is 40.

The spelling of 26504047561 in words is "twenty-six billion, five hundred four million, forty-seven thousand, five hundred sixty-one".