26561624069 has 2 divisors, whose sum is σ = 26561624070. Its totient is φ = 26561624068.

The previous prime is 26561624021. The next prime is 26561624071. The reversal of 26561624069 is 96042616562.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21922651969 + 4638972100 = 148063^2 + 68110^2 .

It is a cyclic number.

It is not a de Polignac number, because 26561624069 - 2²⁸ = 26293188613 is a prime.

It is a super-2 number, since 2×26561624069² (a number of 22 digits) contains 22 as substring.

Together with 26561624071, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (26561624099) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13280812034 + 13280812035.

It is an arithmetic number, because the mean of its divisors is an integer number (13280812035).

Almost surely, 2^26561624069 is an apocalyptic number.

It is an amenable number.

26561624069 is a deficient number, since it is larger than the sum of its proper divisors (1).

26561624069 is an equidigital number, since it uses as much as digits as its factorization.

26561624069 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 933120, while the sum is 47.

The spelling of 26561624069 in words is "twenty-six billion, five hundred sixty-one million, six hundred twenty-four thousand, sixty-nine".