665615500169 has 2 divisors, whose sum is σ = 665615500170. Its totient is φ = 665615500168.

The previous prime is 665615500159. The next prime is 665615500217. The reversal of 665615500169 is 961005516566.

It is a happy number.

665615500169 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 536168095225 + 129447404944 = 732235^2 + 359788^2 .

It is a cyclic number.

It is not a de Polignac number, because 665615500169 - 2⁴ = 665615500153 is a prime.

It is a super-2 number, since 2×665615500169² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (665615500159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332807750084 + 332807750085.

It is an arithmetic number, because the mean of its divisors is an integer number (332807750085).

Almost surely, 2^665615500169 is an apocalyptic number.

It is an amenable number.

665615500169 is a deficient number, since it is larger than the sum of its proper divisors (1).

665615500169 is an equidigital number, since it uses as much as digits as its factorization.

665615500169 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1458000, while the sum is 50.

The spelling of 665615500169 in words is "six hundred sixty-five billion, six hundred fifteen million, five hundred thousand, one hundred sixty-nine".