665877665540281 has 2 divisors, whose sum is σ = 665877665540282. Its totient is φ = 665877665540280.

The previous prime is 665877665540203. The next prime is 665877665540303. The reversal of 665877665540281 is 182045566778566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 555743660014656 + 110134005525625 = 23574216^2 + 10494475^2 .

It is a cyclic number.

It is not a de Polignac number, because 665877665540281 - 2¹³ = 665877665532089 is a prime.

It is a super-2 number, since 2×665877665540281² (a number of 30 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 665877665540198 and 665877665540207.

It is not a weakly prime, because it can be changed into another prime (665877665540881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332938832770140 + 332938832770141.

It is an arithmetic number, because the mean of its divisors is an integer number (332938832770141).

Almost surely, 2^{665877665540281} is an apocalyptic number.

It is an amenable number.

665877665540281 is a deficient number, since it is larger than the sum of its proper divisors (1).

665877665540281 is an equidigital number, since it uses as much as digits as its factorization.

665877665540281 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4064256000, while the sum is 76.

The spelling of 665877665540281 in words is "six hundred sixty-five trillion, eight hundred seventy-seven billion, six hundred sixty-five million, five hundred forty thousand, two hundred eighty-one".