665668505279 has 2 divisors, whose sum is σ = 665668505280. Its totient is φ = 665668505278.

The previous prime is 665668505219. The next prime is 665668505287. The reversal of 665668505279 is 972505866566.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 665668505279 - 2¹⁶ = 665668439743 is a prime.

It is a super-2 number, since 2×665668505279² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665668505219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332834252639 + 332834252640.

It is an arithmetic number, because the mean of its divisors is an integer number (332834252640).

Almost surely, 2^665668505279 is an apocalyptic number.

665668505279 is a deficient number, since it is larger than the sum of its proper divisors (1).

665668505279 is an equidigital number, since it uses as much as digits as its factorization.

665668505279 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 163296000, while the sum is 65.

The spelling of 665668505279 in words is "six hundred sixty-five billion, six hundred sixty-eight million, five hundred five thousand, two hundred seventy-nine".