665126253265 has 4 divisors (see below), whose sum is σ = 798151503924. Its totient is φ = 532101002608.

The previous prime is 665126253241. The next prime is 665126253277. The reversal of 665126253265 is 562352621566.

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 470454694609 + 194671558656 = 685897^2 + 441216^2 .

It is a cyclic number.

It is not a de Polignac number, because 665126253265 - 2⁷ = 665126253137 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66512625322 + ... + 66512625331.

It is an arithmetic number, because the mean of its divisors is an integer number (199537875981).

Almost surely, 2^665126253265 is an apocalyptic number.

It is an amenable number.

665126253265 is a deficient number, since it is larger than the sum of its proper divisors (133025250659).

665126253265 is a wasteful number, since it uses less digits than its factorization.

665126253265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133025250658.

The product of its digits is 3888000, while the sum is 49.

The spelling of 665126253265 in words is "six hundred sixty-five billion, one hundred twenty-six million, two hundred fifty-three thousand, two hundred sixty-five".