665168251277 has 2 divisors, whose sum is σ = 665168251278. Its totient is φ = 665168251276.

The previous prime is 665168251243. The next prime is 665168251283. The reversal of 665168251277 is 772152861566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 569027326921 + 96140924356 = 754339^2 + 310066^2 .

It is a cyclic number.

It is not a de Polignac number, because 665168251277 - 2⁸ = 665168251021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665168551277) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332584125638 + 332584125639.

It is an arithmetic number, because the mean of its divisors is an integer number (332584125639).

Almost surely, 2^665168251277 is an apocalyptic number.

It is an amenable number.

665168251277 is a deficient number, since it is larger than the sum of its proper divisors (1).

665168251277 is an equidigital number, since it uses as much as digits as its factorization.

665168251277 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8467200, while the sum is 56.

The spelling of 665168251277 in words is "six hundred sixty-five billion, one hundred sixty-eight million, two hundred fifty-one thousand, two hundred seventy-seven".