26561657 has 4 divisors (see below), whose sum is σ = 26997156. Its totient is φ = 26126160.

The previous prime is 26561641. The next prime is 26561663. The reversal of 26561657 is 75616562.

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 14318656 + 12243001 = 3784^2 + 3499^2 .

It is a cyclic number.

It is not a de Polignac number, because 26561657 - 2⁴ = 26561641 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 26561657.

It is not an unprimeable number, because it can be changed into a prime (26560657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 217658 + ... + 217779.

It is an arithmetic number, because the mean of its divisors is an integer number (6749289).

Almost surely, 2^26561657 is an apocalyptic number.

It is an amenable number.

26561657 is a deficient number, since it is larger than the sum of its proper divisors (435499).

26561657 is an equidigital number, since it uses as much as digits as its factorization.

26561657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 435498.

The product of its digits is 75600, while the sum is 38.

The square root of 26561657 is about 5153.8002483604. The cubic root of 26561657 is about 298.3676415364.

The spelling of 26561657 in words is "twenty-six million, five hundred sixty-one thousand, six hundred fifty-seven".