665167826117 has 16 divisors (see below), whose sum is σ = 678716879280. Its totient is φ = 651744755712.

The previous prime is 665167826017. The next prime is 665167826143. The reversal of 665167826117 is 711628761566.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 143766855556 + 521400970561 = 379166^2 + 722081^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665167826117 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665167826017) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16359509 + ... + 16400117.

It is an arithmetic number, because the mean of its divisors is an integer number (42419804955).

Almost surely, 2^665167826117 is an apocalyptic number.

It is an amenable number.

665167826117 is a deficient number, since it is larger than the sum of its proper divisors (13549053163).

665167826117 is a wasteful number, since it uses less digits than its factorization.

665167826117 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42152.

The product of its digits is 5080320, while the sum is 56.

The spelling of 665167826117 in words is "six hundred sixty-five billion, one hundred sixty-seven million, eight hundred twenty-six thousand, one hundred seventeen".