26266656501661 has 4 divisors (see below), whose sum is σ = 26537446774972. Its totient is φ = 25995866228352.

The previous prime is 26266656501649. The next prime is 26266656501671. The reversal of 26266656501661 is 16610565666262.

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 14551028205561 + 11715628296100 = 3814581^2 + 3422810^2 .

It is a cyclic number.

It is not a de Polignac number, because 26266656501661 - 2⁵ = 26266656501629 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 26266656501596 and 26266656501605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26266656501671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 135395136510 + ... + 135395136703.

It is an arithmetic number, because the mean of its divisors is an integer number (6634361693743).

Almost surely, 2^{26266656501661} is an apocalyptic number.

It is an amenable number.

26266656501661 is a deficient number, since it is larger than the sum of its proper divisors (270790273311).

26266656501661 is an equidigital number, since it uses as much as digits as its factorization.

26266656501661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 270790273310.

The product of its (nonzero) digits is 27993600, while the sum is 58.

The spelling of 26266656501661 in words is "twenty-six trillion, two hundred sixty-six billion, six hundred fifty-six million, five hundred one thousand, six hundred sixty-one".