26611705661 has 4 divisors (see below), whose sum is σ = 26630976924. Its totient is φ = 26592434400.

The previous prime is 26611705651. The next prime is 26611705721. The reversal of 26611705661 is 16650711662.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 18954405625 + 7657300036 = 137675^2 + 87506^2 .

It is a cyclic number.

It is not a de Polignac number, because 26611705661 - 2¹⁸ = 26611443517 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26611705651) 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 3 ways as a sum of consecutive naturals, for example, 9633560 + ... + 9636321.

It is an arithmetic number, because the mean of its divisors is an integer number (6657744231).

Almost surely, 2^26611705661 is an apocalyptic number.

It is an amenable number.

26611705661 is a deficient number, since it is larger than the sum of its proper divisors (19271263).

26611705661 is a wasteful number, since it uses less digits than its factorization.

26611705661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19271262.

The product of its (nonzero) digits is 90720, while the sum is 41.

The spelling of 26611705661 in words is "twenty-six billion, six hundred eleven million, seven hundred five thousand, six hundred sixty-one".