266620877557 has 2 divisors, whose sum is σ = 266620877558. Its totient is φ = 266620877556.

The previous prime is 266620877521. The next prime is 266620877617. The reversal of 266620877557 is 755778026662.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 253330015761 + 13290861796 = 503319^2 + 115286^2 .

It is a cyclic number.

It is not a de Polignac number, because 266620877557 - 2¹⁹ = 266620353269 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 266620877495 and 266620877504.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (266620877057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 133310438778 + 133310438779.

It is an arithmetic number, because the mean of its divisors is an integer number (133310438779).

Almost surely, 2^266620877557 is an apocalyptic number.

It is an amenable number.

266620877557 is a deficient number, since it is larger than the sum of its proper divisors (1).

266620877557 is an equidigital number, since it uses as much as digits as its factorization.

266620877557 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 59270400, while the sum is 61.

The spelling of 266620877557 in words is "two hundred sixty-six billion, six hundred twenty million, eight hundred seventy-seven thousand, five hundred fifty-seven".