660520169 has 2 divisors, whose sum is σ = 660520170. Its totient is φ = 660520168.

The previous prime is 660520117. The next prime is 660520181. The reversal of 660520169 is 961025066.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 656025769 + 4494400 = 25613^2 + 2120^2 .

It is a cyclic number.

It is not a de Polignac number, because 660520169 - 2⁸ = 660519913 is a prime.

It is a super-2 number, since 2×660520169² = 872573787311577122, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (660526169) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330260084 + 330260085.

It is an arithmetic number, because the mean of its divisors is an integer number (330260085).

Almost surely, 2^660520169 is an apocalyptic number.

It is an amenable number.

660520169 is a deficient number, since it is larger than the sum of its proper divisors (1).

660520169 is an equidigital number, since it uses as much as digits as its factorization.

660520169 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 19440, while the sum is 35.

The square root of 660520169 is about 25700.5869388230. The cubic root of 660520169 is about 870.8874412254.

The spelling of 660520169 in words is "six hundred sixty million, five hundred twenty thousand, one hundred sixty-nine".