26404345661 has 4 divisors (see below), whose sum is σ = 26418325500. Its totient is φ = 26390365824.

The previous prime is 26404345613. The next prime is 26404345679. The reversal of 26404345661 is 16654340462.

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 12313231225 + 14091114436 = 110965^2 + 118706^2 .

It is a cyclic number.

It is not a de Polignac number, because 26404345661 - 2³⁴ = 9224476477 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 (26404345601) 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, 6987086 + ... + 6990863.

It is an arithmetic number, because the mean of its divisors is an integer number (6604581375).

Almost surely, 2^26404345661 is an apocalyptic number.

It is an amenable number.

26404345661 is a deficient number, since it is larger than the sum of its proper divisors (13979839).

26404345661 is a wasteful number, since it uses less digits than its factorization.

26404345661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13979838.

The product of its (nonzero) digits is 414720, while the sum is 41.

The spelling of 26404345661 in words is "twenty-six billion, four hundred four million, three hundred forty-five thousand, six hundred sixty-one".