26661895657 has 2 divisors, whose sum is σ = 26661895658. Its totient is φ = 26661895656.

The previous prime is 26661895621. The next prime is 26661895669. The reversal of 26661895657 is 75659816662.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25937424601 + 724471056 = 161051^2 + 26916^2 .

It is a cyclic number.

It is not a de Polignac number, because 26661895657 - 2¹⁹ = 26661371369 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 26661895595 and 26661895604.

It is not a weakly prime, because it can be changed into another prime (26661892657) 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, 13330947828 + 13330947829.

It is an arithmetic number, because the mean of its divisors is an integer number (13330947829).

Almost surely, 2^26661895657 is an apocalyptic number.

It is an amenable number.

26661895657 is a deficient number, since it is larger than the sum of its proper divisors (1).

26661895657 is an equidigital number, since it uses as much as digits as its factorization.

26661895657 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 32659200, while the sum is 61.

The spelling of 26661895657 in words is "twenty-six billion, six hundred sixty-one million, eight hundred ninety-five thousand, six hundred fifty-seven".